Topic 28 "Fuels from under the ground": your read (2 October 2026)

Two readers answered 111 items cold and caught three wrong oil keys before anything else moved: both answered "a thick dark liquid" where the bank keyed "a black rock" (PP-12), and "tiny living things of long-ago seas" where it keyed "plants of long-ago swamps" (PP-13, PP-37). The readers were right. The cause was the bank's helper that rotates a fixed option set so the key lands at a chosen letter: it keys the set's first member, and three oil items had rotated the coal-first set without putting the oil member first. Fixed by putting the asked-for member first in every oil and gas call, and a script then checked every bank key's text against its why line (0 mismatches). Their other flags, all applied in v2: twelve key tells; an option ("They came from a tree") defensible beside the course's own "coal was once plants"; two options both true of oil; a distractor true of a gas-turbine plant; a car that must not burn natural gas beside a truck that did; "shale", "blacksmith", "oil field" and "gas field" in stems no lesson had said; shared option sets and give-away pairs; a candle burned for light; wider accept lists for "fuel" / "fuels".

Reader C then read the whole v2 bundle, 116 items, and agreed every key; every oil item had one true option. Three items would not ship as they stood: PP-07, PP-16 and PP-35, each a key a child could pick by its shape (the only option not starting "They"; the only bare noun; the only option with "and"); PP-32 needed a draw constraint because PP-44 and PR-8 both say the gas sits above the oil. Three softer tells (PP-19, PP-34, PP-49) and one in a quiz (L02-02); a stem that read oddly after re-scening (PP-28); a stray comma in one card's data; six words no lesson line had said; and Maria beside Lara. All applied in v3, keys unchanged.

The science is sound at Grade 4 depth and the teaching shape is right, the reviewer said: each fuel gets what-it-is, where-from (a four-panel strip) and what-we-burn-it-for; the "fuel" coin is earned by the three-card run with sunlight as the honest near miss; the dinosaur, lake, made-at-the-station and "nature makes more soon" beliefs are each met by a lesson line and an item. Three things had to change, and did: the power-plant chain said "the wheel makes electricity" where Topic 27 says the steam pushes the wheel round and the turning wheel turns a machine that makes electricity (now Topic 27's words everywhere); ten key tells; two TRUE-claim items were the previous item's feedback read back (now a pump brings the oil up; the furnace burns natural gas). Worth fixing, all done: the candle, "power plant" unexplained in the L01 video, "natural gas" in two stems that asked for "a gas", a belief with no lesson line (L03 now says "Natural gas is not air. Air does not burn."), "run out", the names, "energy source". The reviewer answered the author's five questions as the page above shows, and gave the cross-topic word rulings in questions 6 to 8.

What a student notices first is the three story strips: four panels left to right, one arrow size, a chip under each; swamp, mud, pressed, coal reads at a glance, and the oil-and-gas strip shows the gas band above the oil. Four fixes before the cold read, all made: the two item-card drawings were 5 px text on a phone (now three stacked cards at 15 px); the power-plant chain had no carrier chips and a floating flame (now Topic 27's own chain card, imported); coal grew thicker after pressing (equal bands); a wire sat on a chip (icon lifted). The page pass found the rule cards duplicating the rule box and the four tables illegible on a phone: rule cards are out of the articles (kept for the videos), and every table is a stacked two-column block, one per fuel. Minor: a roof closed, a well tower given rungs, the oil band matched to Topic 19's limestone, labels enlarged.

51 items in content/G4T28_pp100_bank.py: 47 four-option MCQs, 3 typed words (coal, fuel, oil) and one two-of-four select (the two fuels from the sea). Per atom: EAR4-087 17 · EAR4-088 17 · EAR4-089 17. Easy 20, medium 20, hard 11, sorted easy to hard and rising with the atom's place in the topic. MCQ keys A 13 · B 11 · C 12 · D 11. Eleven question types, one exemplar each on the type sheet: which fuel fits a clue; what a fuel started as; what the power plant or factory makes and what the burning fuel does; which thing is a fuel and why; how a fuel is got out and where it sits; what the place was like when a layer formed; trace a machine or product back to its fuel; what is true of long-pumped rock; a child's claim is wrong, pick the reason; which drawn card describes a fuel; type the fuel from its origin. Every scene is fresh against the lessons, quizzes and practice (the scene-noun grep is in the build record), and the type sheet lists the draw constraints, including the new one from Reader C.

Skill: course-build → write-lesson → write-example-sequence, design-check-sequence, sentence-atomise, write-explanation, write-mcqs; write-video-script; review-figures (author self-check) @ efd8fba

_Skill detail: course-build → write-lesson (L01 a concept introduction in the fact form with a short classification run coining fuel; L02 a fact lesson recalling Topic 19's sentence; L03 the capstone fact lesson, the second face joined with also, closing on the three-fuel table) → write-example-sequence, design-check-sequence, sentence-atomise, write-explanation, write-mcqs (quizzes, attached questions, practice, the PP100 bank and its type sheet); write-video-script (intro, three lesson scripts, summary; the elementary micro-lesson anatomy); review-figures (author self-check on the renders and the built page; the non-author pass is owed)._

Grade 4 Topic 28 — Fuels from under the ground — build record (v1, 2 October 2026)

What this is, in plain words

Three short lessons, one per atom, in register order. A child first meets a rock that burns: Maria's grandpa tips black lumps into his stove and they glow red, and the lesson answers "how can a rock burn?" by showing that a log burns, coal burns, sunlight is not burned (so "a thing people burn to get heat is called a fuel"), and then that coal was once plants: swamp plants, buried in mud, pressed for a very long time, dug up and burned in a power plant to make electricity (L01). Next, Micah watches a pump nod in a Texas field and asks whether a lake of oil lies under it; the lesson recalls Topic 19's sentence word for word (the oil sits in the rock's tiny spaces, the way water sits in a sponge, not in an underground lake), tells where oil came from (tiny living things of long-ago seas, buried and pressed) and follows it up the well, through the factory to gasoline, into a car's engine (L02). Last, Mariana's dad lights the stove's blue flame and she asks whether it is the same gas as the car's: the lesson tells natural gas from gasoline in a two-column table, tells the second face of L02's story ("Natural gas also formed from them", trapped in the rock above the oil), follows the gas up a well and through pipes to stoves, furnaces and power plants, and closes the topic on the three-fuel table and two plain lines that these three are not like Topic 27's sources: nature does not make more in our lifetimes (L03). "Nonrenewable" and "fossil fuel" are left to Topic 29.

Counts. 3 lessons · 3 scripts (148, 148, 147 spoken words) + intro (120 words, 3 question marks) + summary (152 words) · 3 attached questions + the intro's poll + 3 summary questions · 36 quiz items (13 + 12 + 11; 8 of them claim items, 2 typed) · 18 practice items (14 MCQ, 1 written answer, 3 typed; three Grade 3 retrievals and one Topic 19 retrieval; "fuel", "coal" and "oil" offered then typed, "natural gas" and "power plant" recognised and recalled by MCQ) · PP100 bank 51 items (47 four-option MCQs, 3 typed, 1 multi-select; EAR4-087 17, EAR4-088 17, EAR4-089 17; easy 20, medium 20, hard 11; MCQ keys A 13 · B 11 · C 12 · D 11) · 30 figures (19 SVG by code, 8 photo placeholders, 3 cartoon placeholders; one imported read-only from Topic 19). Articles 365 / 374 / 418 words (see "WARNs answered").

Decisions made without a blueprint

One line each, with the reason:

• Three lessons, one per atom, in register order — the architecture row names three Fact atoms and the capstone closes the topic; each payoff is one clause, so nothing needed splitting.
• "Fuel" is coined in L01 by a three-card run, before coal's story — the title says "Fuels"; Topic 29 will sort seven sources and needs the word; the run is a classification, so write-example-sequence's frame rule applies; sunlight is the near miss (a Topic 27 energy source that warms but is not burned), chosen because a child could believe every energy source is a fuel; granite was rejected as the non-example because "a rock does not burn" is the child's default, not a near miss.
• "Coal" and "power plant" are coined in L01, "natural gas" in L03; L02 never says "natural gas" — S12 forbids a term before its coining lesson, so Topic 19's sentence is recalled in its oil form ("The oil sits in the rock's tiny spaces, the way water sits in a sponge, not in an underground lake" — L04's own words) rather than its full "water, oil or natural gas" form.
• "Gasoline", not "petrol"; "power plant", not "power station" — US words for US children (the register's examples use the UK words; the behaviour is unchanged). "Gasoline" is glossed, not coined ("the liquid that goes into a car's tank"); it is in RECALL_BY_MCQ because an 8-letter word a child calls "gas" is not a fair typed key.
• The where-from stories are ONE strip shape (four panels, arrows, a chip under each), with coal's panels and oil's panels, and the oil-and-gas variant registered for L03 only — the brief's shape; the two oil strips never share a page.
• Oil in the rock's tiny spaces is Topic 19's drawing, imported read-only — one depiction per thing; the strip's last panel draws only a tan band with dark drops (and pale blue circles above for the gas), never a second lens.
• The power plant mechanism is one step row (coal burns → heat boils the water → steam turns the wheel → electricity) in the article and the summary bullets, and one spoken clause in L01's script — TEKS G4-11A's example is "to make electricity"; without the wheel "makes electricity" is a bare word. "A big wheel", never "turbine"; "the heat carries energy to the water" (heat carries energy).
• L03 carries the three-fuel table and the two contrast lines — the brief asked for the contrast with Topic 27 in one line without coining "nonrenewable"; "nature keeps giving them" is the phrase the brief gave; Topic 27 is not on disk (checked), so the card shape could not be matched — see Questions.
• "Fossil fuel" is not said — the register does not name it (checked: EAR4-087/088/089 cross notes name only the TEKS list); Topic 29's sort may coin it.
• No years anywhere — "a very long time" (Topic 21's phrase), "long-ago swamps / seas"; "millions of years" (Grade 3 Topic 27's words) is not repeated.
• Every lesson gets a video — each is a story a child should watch unfold (the strip, the pump, the flame).
• The intro is one car trip (Wyoming: the coal train, the nodding pumps) with the stove at home as its second opener, two felt questions, the map line naming only things a child can picture, no coin, no pointing at L01's cabin or L02's gas station.
• "Natural gas" and "power plant" in RECALL_BY_MCQ — two-word terms; "coal", "oil" and "fuel" are typed (short, spellable, with child spellings accepted).

Grade 3 and Grade 4 doorways, recalled by one item and one line each, never re-taught: Grade 3 Topic 28 L01 ("A thing we take from nature to make things or to use is called a natural resource"; "Plastic is made from oil. The oil sits deep under the ground, and a pump brings it up") — L01-q1, L02-q1, PR-1, PP-51; Grade 3 Topic 28 L02 ("A natural resource runs short when people use it faster than nature replaces it") — PR-3; Grade 3 Topic 27 L01 ("After a living thing dies, its body usually rots away and becomes part of the soil") — PR-2 and L01's "mud covered them before they could rot away"; Grade 4 Topic 19 L04 ("A rock with tiny spaces between its grains … can hold water, oil or natural gas, like a sponge"; "The oil sits in the rock's tiny spaces, the way water sits in a sponge, not in an underground lake") — L02's recall line, L02-q2, PR-4, PP-25; Grade 4 Topic 21 ("the bottom layer formed first"; "pressed together over a very long time") — PP-24, PP-50. Grade 4 Topic 27 (not on disk): "nature keeps giving them" in L03 and PR-12.

The simplification, named: "pressed" for burial, pressure and heat over geological time; "mud covered them before they could rot away" for waterlogged peat; "often right above the oil" for a gas cap (natural gas also occurs alone — "often"); "the gas pushes up the pipe by itself" for reservoir pressure; "a factory" for a refinery; "a big wheel" for a turbine. No note is printed in the articles.

Questions for James (the build does not wait on them)

1. Should "fossil fuel" be said once here as the group's name, or left to Topic 29? The register does not name it; the three strips all end in "from living things long ago", which is the word's reason. I left it out and built the three-fuel table as the group's picture; recommendation: Topic 29 coins it with the sort.
2. "Fuel" is coined in L01 — if Topic 27 (being written now) coins it first for the burning logs, L01's coin becomes a one-line recap. Recommendation: whichever topic ships first keeps the coin; the other's agent swaps to the recap form (one line each).
3. L02's rule lost "the tiny spaces of" to fit the 150-word script ("People pump oil up from deep rock, make gasoline from it, and burn the gasoline in car engines"); the tiny-spaces idea stays in the forest, the article, the Topic 19 recall and the attached question. Recommendation: keep the shorter rule.
4. Maria and Mariana are the pool's names for this row and look alike on a page. Recommendation: keep (the pool is yours), or swap Mariana for a different-shaped name course-wide if Olivia trips on it.
5. The articles run 365 / 374 / 418 words against the 300 WARN — each lesson carries three jobs (what it is, where it came from, what we burn it for) and L03 carries the capstone close; a subtitle or figure sits every six idea lines or fewer. Recommendation: accept; the alternative is a fourth, short "three fuels" article split off L03 with a check between.

Design-check-sequence records

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Skill: design-check-sequence @ efd8fba

Part: L01 (one part), coal

Type: (a) one-step categorisation and facts — the atom is "describe coal, then how people get energy from it"; the fuel coin is a one-step sort; the beliefs (always there; made at the power plant) take type (c) claim items.

Plan: 13 items: recall (Grade 3 resource, 3 opt) → charcoal yes / sunlight no → what is coal (3) → power plant recognition (3) → where coal started (3) → the reason coal burns (3) → Micah's claim (no) → Mariana's claim (no) → candle wax (yes) → fuel recognition (3) → coal recognition (3) → typed coal. Two-option string A B B B A (B 3 of 5 = 60 %); three-option 1 0 1 2 0 2 1.

Belongs in practice/bank instead: the power plant's steps in order (PR-9); the reason-picking forms; the typed fuel (PR-16).

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Part: L02 (one part), oil

Type: (a) facts, with type (c) claims on the documented beliefs (a lake; dinosaurs) and one TRUE claim (the sponge) for the key balance.

Plan: 12 items: Grade 3 recall (plastic, 3) → Topic 19 recall (the sandstone drop, 3) → what is oil (3) → where in the rock (3) → where it started (3) → Maria's lake (no) → Mariana's sponge (yes) → Micah's dinosaurs (no) → gasoline recognition (3) → the bus's gasoline (3) → which came first (2) → typed oil. Two-option string B A B A; three-option 2 1 0 2 1 0 1.

Belongs elsewhere: the lettered-layer comparison (PP-25); the long-pumped field (PP-31).

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Part: L03 (one part), natural gas — the capstone

Type: (a) facts, with type (c) claims (the gas at the pump; nature makes more in a few years) and one TRUE claim (the same tiny living things).

Plan: 11 items: which fuel is the liquid (3) → what is natural gas (3) → which thing burns it (3) → the bus's tank (2) → where it started (3) → where it is found (3) → Maria's TRUE claim (yes) → Micah's pump claim (no) → the power plant (3) → Mariana's few-years claim (no) → natural gas recognition last (3; RECALL_BY_MCQ). Two-option string A A B B; three-option 1 0 2 0 1 2 0.

Belongs elsewhere: the three-fuel sort by cards (PP-39, PP-40); the two-fuel trace (PP-49).

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Order rule: each quiz climbs recognise → apply → produce; the typed item is last; every recognition MCQ precedes its typed twin (S33 clean).

The key strings

• Attached questions in video order (L01, L02, L03, S1, S2, S3): B A B A B A (A 3 of 6).
• L01 two-option A B B B A; three-option 1 0 1 2 0 2 1. L02 two-option B A B A; three-option 2 1 0 2 1 0 1. L03 two-option A A B B; three-option 1 0 2 0 1 2 0.
• Practice two-option B B B (the three claims are all No — Maria's gas station, Micah's wind-and-sunlight, and PR-3's "runs short" is a two-of-three item, not a claim; one TRUE practice claim would improve this: see judgement calls); three-option 2 0 1 2 0 1 2 1 0 0 1.
• Bank MCQ keys A 13 · B 11 · C 12 · D 11; full string in G4T28_pp100_bank.py's __main__ print: B C A C D B C D B C A D B A C B D B C B B D A B A C D D D B B A C B C A D C C B T T T D C B D M B C C (before the final rotation; the current counts are above).

The example sequence, written out (L01's fuel run)

Frame: "People burn <it> to get heat." Cards: a log (E) → coal (E) → sunlight (NE, "The sunlight warms the wall, but nobody burns sunlight"). Connectives: "Here is… / Here is… / And here is…". Rule after the run, so no because on the frames; the coin "A thing people burn to get heat is called a fuel." then the split restatement "A log is a fuel, and coal is a fuel. Sunlight is not a fuel." The verdict figure prints its question above the marks ("Do people burn it to get heat?"); the headache form carries no chips. Transfer checks on unseen cases: charcoal (yes), a solar panel's sunlight (no), a candle's wax (yes), dry sticks (PP-7).

The rules applied

Misconceptions confronted, by name

The catalogue (Elementary physics misconceptions catalogue (grades 3-5).md) has no fuel rows; its ENE-04 (energy as a stuff in a tank) is avoided by wording (above). The Earth-science beliefs below come from the literature named:

Checker result, every WARN answered

python3 build_tools_check_topic.py grade4/topic28_build/content/G4T28.py → 0 FAIL, 18 WARN. python3 grade4/check_g4_articles.py … → 0 FAIL (scripts 148 / 148 / 147; intro 120; summary 152 with the opener; articles 365 / 374 / 418 WARN above 300).

• S8 (5) script beats of three sentences — kept; each beat is one screen state (the demo's and Topic 22's accepted shape).
• S36 (13 words), each answered: charcoal ×6 (L01-q2: a US child knows a charcoal grill; the item's point is that it is burned for heat — fine); furnace ×6 (the US household word for the heater; the atom's "piped to where it is burned" needs a second burner beside the stove — fine, kept in the lexicon); scooped ×3 (an everyday verb in HOW4's distractor — fine); shale ×2 (Topic 18's coined rock name, two topics old — fine); jet ×2 ("jet fuel" beside "airplane" — fine); museum, pizza, restaurant, barbecue, grill, spark, salty, van (everyday words a nine-year-old owns — fine). hollow (James's note) was swapped for "empty space" in both places it appeared.
• Articles above 300 words — answered in Questions for James 5: three jobs per lesson and the capstone close; a subtitle or figure every ≤ 6 idea lines; no stretch of text runs long.
• Clean: S1–S7, S9–S15, S17, S20–S35, S37–S39 (S29 0 after "burns natural gas" replaced "runs on"; S30 typed 8, 0 fail, 0 warn).
• Tool note for the coordinator (not changed here): the checker prints "(could not load G4T26.py: module 'figures' has no attribute 'Q1_LETTERS')" while reading the course's other topics — Topic 26's content, not this topic's.

Bank freshness, re-performed

Scene nouns of the lessons, quizzes, attached and summary items (grandpa, cabin, Pennsylvania, bucket, shed, campfire, sunlight, wall, Louisiana, Vermont, charcoal, barbecue, grill, solar, Arizona, candle, wax, Ohio, Wyoming, train, gas station, Texas, tank, nods, North Dakota, Florida, Alaska, Georgia, Nevada, Kansas, Oklahoma, Michigan, pancake, kitchen, stove, pizza, museum, Kentucky, Colorado) were grepped against the bank and the practice set. After the edits: bank hits are "gas station" ×4 (PP-33, PP-46 and the two gasoline-against-natural-gas items — the atom's own confusion needs the word; the scene in each is a van, a heater, a claim, never Micah's forecourt) and Colorado ×2 (a well, a cliff — a state name, not a scene); "bucket" and "sunlight" were re-scened out of PP-16, the Kentucky cliff became Alabama, the summary's pizza oven moved to New York. Practice hits: "gas station" ×2 (PR-11's claim, PR-13's distractor), "sunlight" (PR-12's Topic 27 contrast), "Kentucky" (the FRQ hillside against the summary's museum — a state, not a scene). The template inventory (51 rows) is on the type sheet; 14 items are NEW moves, the rest share a lesson fact with a new scene kind and are marked draw-one-per-test where two bank items share a move.

Blind-text grep

python3 build_tools_blind_bundle.py grade4/topic28_build/content/G4T28.py grade4/topic28_build/blind/2026-10-02 → bundled 101 mcq, 8 text, 1 frq, 1 multi (111 held). grep "[Drawing:" … | grep -iE "coal|oil|gas|swamp|sea|pressed|buried" → 2 hits, both the card rows: card J: a thick dark liquid, pumped up a deep well; card K: a black rock, dug out of a mine; card N: a gas you cannot see, sent through pipes and card P: a gas that burns, with a blue flame; card R: made into gasoline, at a factory; card T: formed from plants, of long-ago swamps. Each is the card's printed words — the item's DATA, which the reader needs to answer "which card describes natural gas / oil"; neither line says which card is which fuel. No other item figure carries blind text (no verdict words, no match letters).

Figures (author self-check on the renders and the built page; the non-author review-figures pass is owed)

Rendered every SVG to /tmp/g4t28_figs/png/ with headless Chromium and opened: the two strips (panels in order, arrows between, chips under; the gas variant's "gas" and "oil" labels moved left of the dots after the first render overlapped them), the fuel cards (question above, chips and marks below, the headache form bare), the three step rows (the power-plant icon's wire moved under its factory after the first render overlapped), the three tables (every cell inside its column — Topic 18's guard), the two card rows, the rule cards, Topic 19's lens. check_svg_ids.py → PASS (30 figures, 0 ids). The built page (/tmp/g4t28.html) screenshotted on each lesson's article and quiz route at phone width and read: every figure in place, captions under, no empty box. Depiction register in figures.py's docstring.

Names run

python3 build_tools_names.py Petrov Maria Mariana Micah → Petrov free · Maria free · Mariana free · Micah free · exit 0. No other name appears in a student-facing string (Grandpa, Mom and Dad are relations, not names).

Sentence-atomise self-check (one table per paragraph, collapsed to the rows that changed)

Judgement calls

1. Sunlight as the fuel run's non-example (not granite): the child's belief that needs the boundary is "every energy source is a fuel"; "a rock does not burn" is the default, so granite would have been an absurd case for the run (it still serves as the quiz's "coal burns, granite does not" reason item).
2. The power-plant mechanism (steam, a big wheel) is one step beyond "burned to make electricity"; kept because TEKS' example needs a picture, and Topic 12 taught that moving things can turn things.
3. "Often right above the oil" for natural gas — true of a gas cap, hedged with "often" because many gas fields have no oil; the strip's variant draws the gas band above the oil band.
4. Charcoal counted as a fuel (L01-q2) — made from wood, burned for heat; it never appears as a fuel "from under the ground".
5. The practice set's three claims are all No — Maria's gas station, Micah's wind-and-sunlight, and no TRUE claim; the lesson quizzes carry three TRUE claims (Mariana's sponge, Maria's same-things, Maria's charcoal), so the topic's claim balance is 3 yes / 7 no across quizzes and practice. A TRUE practice claim would help; left for the review.
6. "Louisiana" swamp photo as the analogue for long-ago coal swamps — the caption says "looked something like this"; no claim that coal is forming there.
7. Topic 27 absent from disk — "nature keeps giving them" is used as the brief gave it; if Topic 27's wording differs, L03's line and PR-12 take Topic 27's words (one line each).
8. The intro's "all three come from under the ground" and the rock-oil-gas map line name coal as "a black rock that burns" — no coining ("is called" absent); the checker's S15 / S20 pass at 120 words.

Owed

• The non-author passes: review-questions over the quizzes, practice and bank (its check 26 reads the inventory on the type sheet), review-figures over the 30 renders, review-accuracy on the mechanism lines (peat, gas cap, pressure), then the blind read of blind/2026-10-02/ by two cold readers and the adjudication.
• The picture pass (David's pack) for the 8 photo and 3 cartoon placeholders — waits for James's answers to the questions above, per the brief's sequencing rule.
• Videos: handoff/G4T28/videos/batch_G4T28.json and READY.md are written and check_brief.py is clean except the intro's standing closing-bullets hit (an intro has no rule slide; the same hit stands on Topic 22's intro). NOT sent — James's word is needed for Grade 4's first batch.
• Nothing committed.

v2 — reviews applied (2 October 2026)

Skill: course-build → write-lesson (the chain sentence, the L03 split, the L04 article) → write-video-script (L01 beat 5, the L04 script, the summary's fifth beat) → write-mcqs (every item change; check_key_tells.py to 0) → write-explanation (every new fb and why) → review-figures (author re-render of every changed key and the built page) @ fb37d14

In plain words. Three reviews found a sound topic with a handful of real faults, and all are fixed. The power-plant chain now says what Topic 27 says — the steam pushes a big wheel round, and the turning wheel turns a machine that makes electricity — in the article, the figure, the practice item and every why. The L01 video now names the power plant. Two TRUE-claim items that the previous item's feedback had answered are new claims (a pump brings the oil up; the furnace burns natural gas). Mariana is now Lara, so no two children's names look alike. The long L03 article is two lessons: L03 (natural gas) and a short L04 capstone, "Three fuels from under the ground", with a six-item quiz between (L03's old first item leads it). Ten key tells are gone, every untaught word in a stem (shale, blacksmith, oil field, gas field) is gone, three "run out" strings say "run short", and the figures that were postage stamps on a phone — the item cards and the four tables — are stacked. Blind bundle re-cut; the batch rebuilt and checked; nothing sent, nothing committed.

#### Finding → change

#### Checker lines

• build_tools_check_topic.py → 0 FAIL, 19 WARN (S8 beats of three sentences ×5, as v1; S18 L04's quiz has six items — a one-idea capstone, by the "fewer, never padded" rule; S36 as v1 plus petrov ×3 — the row's teacher, named in L04's headache for the first time; heavier was fixed, not kept).
• check_g4_articles.py → 0 FAIL: articles L01 371 · L02 374 · L03 356 · L04 208 (all ≤ 400; L03's two parts shorter than the old 418); scripts 150 / 148 / 147 / 106; intro 120; summary 175 with the opener.
• check_key_tells.py → KEY TELLS: 0 of 107 MCQs flagged (a: 0, b: 0, c: 0).
• build_tools_names.py Petrov Maria Lara Micah → Petrov free · Maria free · Lara free · Micah free · exit 0.
• check_svg_ids.py → PASS (31 figures, 0 ids).
• Batch: build_tools_video_batch.py → 6 videos (intro 120, L01 145, L02 143, L03 143, L04 102, summary 169 by its count); check_brief.py ✓ on L01–L04 and the summary, the intro's standing closing-bullets line (an intro has no rule slide). grep -ci strand → 0. Not sent.
• Blind bundle: blind/2026-10-02-v2/ — 106 MCQ, 8 text, 1 FRQ, 1 multi (116 held). grep "[Drawing:" | grep -ciE "coal|oil|natural gas|swamp|sea|pressed|buried|plants" → 0 hits (the two card rows print only their cards' words, none of them a fuel name or an origin word).
• Site built to /tmp/g4t28_v2.html; the four article routes, the L04 quiz and the PP100 route screenshotted at 1200 px and in a 360 px iframe and read: the stacked tables and cards read on the phone; the chain card's chips sit clear of its boxes; no empty box. Per-key renders opened: power_plant_steps, pp_cards_jkn, pp_cards_prt, table_fuels_one / _three, table_gas_vs_gasoline, strip_coal, strip_oil, strip_oil_gas, gas_to_stove_steps, oil_to_car_steps, fuel_cards_verdicts, rule_three.

#### The _rot audit

Every _rot(...) and _name(...) call read against its stem: coal items rotate WHAT4 / FROM4 / HOW4 / NAME4 with coal first; oil items use WHAT_OIL, HOW_OIL, FROM4[1:] + FROM4[:1], SITS4 and _name(1, k); natural gas items WHAT4[2:] + WHAT4[:2], HOW4[2:] + HOW4[:2], FROM4[1:] + FROM4[:1] and _name(2, k). A script then checked every bank MCQ's keyed option against its why line (20 fixed-set items, 0 mismatches). _rot's docstring now says the caller puts the asked-for member first.

#### Key strings

• Attached, video order (L01, L02, L03, L04, S1, S2, S3): B A B B A B A (B 4 of 7).
• L01 two-option A B B B A; three-option 1 0 1 2 0 2 1 (unchanged). L02 two-option B A B A; three-option 2 1 0 2 1 0 1. L03 two-option A A B; three-option 0 2 0 1 2 0. L04 two-option A B; three-option 1 2 0 0. Practice two-option B B B; three-option unchanged.
• Bank MCQ keys A 13 · B 11 · C 12 · D 11; 51 items (17 / 17 / 17; easy 20, medium 20, hard 11).

#### Item ids changed

Lessons: L01-09 (name), L01-10, L01-12, L01-13 (scenes) · L02-05 (option text), L02-06 (stem), L02-07 (new claim) · L03-01 → L04-01 (moved), L03-02 (stem), L03-03 (options), L03-05 (option text), L03-06 (key text), L03-07 (new claim), L03-09 (fb, why), L03-10 → L04-05 (moved, renamed) · L04-01…06 and L04-V-01 (new lesson). Practice: PR-2, PR-8 (option text), PR-9 (options, fb, why), PR-17 (scene). Bank: PP-5, 7, 12, 14, 18, 21, 23, 24, 31, 32, 34, 36, 38, 45, 46, 47; card T's words (PP-40's drawing and blind text). Summary: Q2 option text; a fifth beat; the chips.

#### Judged differently, and why

• "a big wheel" stays in L01 and PR-9: the blind readers flagged it as unsaid, but L01's article says "a big wheel" and the chain card now draws it; only the PP stems' untaught words (shale, blacksmith, oil field, gas field) were removed.
• L04's script does not say "energy resource" (the article does, with its one-line meaning): the batch builder's banned list includes "energy" and Topic 28 has no UNBAN row; the video speaks "nature keeps giving them", Topic 27's own phrase.
• Lara is the pool's only freed name (Topic 23 released it for Lydia). Topic 23's figures.py still names Lara in three cartoon notes (David-facing, not student text) — Topic 23's pass should swap them to Lydia.
• The chain card is 572 units wide (four boxes), so on a phone its box text is about 7 px — Topic 27's own three-box cards have the same scale; the figure review asked for this card shape, and one depiction per thing wins.

Not committed.

v3 — polish (2 October 2026)

Skill: course-build → write-mcqs (every item change; check_key_tells.py at 0) → write-explanation (every changed fb and why) → write-lesson (two article lines) @ e23b67f

In plain words. A third cold reader (Reader C) read the whole v2 bundle, 116 items, and agreed every key; no second option was defensible anywhere. What was left was shape: three bank keys a child could pick by their look alone, three softer length or comma tells and one in a quiz, one bank stem that reads oddly after its re-scening, one in-bank give-away (two stems say the gas sits above the oil, which another item asks), a stray comma in a card's blind text, six words no lesson line had said, and two girls' names that rhyme. All applied; no key letter, key meaning, tag or figure changed. The second girl is now Joy (not Lara). Blind bundle re-cut; batch rebuilt, not sent; nothing committed.

#### Flag → change

#### Checks after v3

• python3 build_tools_check_topic.py grade4/topic28_build/content/G4T28.py → 0 FAIL, 17 WARN (v2's 19 less the two "charcoal" hits; S8 ×5 beats of three sentences, S18 L04's six-item quiz, S36 furnace ×10, petrov ×3, scooped ×3, museum, pizza, restaurant, barbecue, grill, spark, salty, van — all answered in v1/v2).
• python3 grade4/check_g4_articles.py grade4/topic28_build/content/G4T28.py → 0 FAIL (articles 381 / 376 / 356 / 208; scripts 150 / 148 / 147 / 106; intro 120; summary 175, opener ok).
• python3 ~/Documents/CourseBuilding-Vault/skills/write-mcqs/check_key_tells.py grade4/topic28_build/content/G4T28.py → KEY TELLS: 0 of 107 MCQs flagged (a: 0, b: 0, c: 0); KEY LONGEST (any margin) 49 of 107, fixed-set exempt 34.
• python3 build_tools_names.py Petrov Maria Joy Micah → Petrov free · Maria free · Joy free · Micah free · exit 0.
• python3 ~/Documents/CourseBuilding-Vault/skills/review-figures/check_svg_ids.py grade4/topic28_build/content/figures.py → PASS (31 figures, 0 ids).
• python3 build_tools_build_topic_site.py grade4/topic28_build/content/G4T28.py /tmp/g4t28_p.html → 4 lessons, 18 practice, 51 pp100, 31 figures.
• Batch rebuilt (build_tools_video_batch.py; the L03 script's first beat names Joy): 6 videos, key string B A B B A B A; check_brief.py ✓ on L01–L04 and the summary, the intro's standing closing-bullets line (an intro has no rule slide). grep -cw Lara → 0; grep -ci strand → 0. Not sent.
• Blind bundle re-cut: blind/2026-10-02-v3/ — 106 MCQ, 8 text, 1 FRQ, 1 multi (116 held); keys sequestered. grep "[Drawing:" | grep -ciE "coal|oil|natural gas|swamp|sea|pressed|buried|plants" → 0; card R's line reads "made into gasoline at a factory"; "Lara" → 0 hits.

#### Counts and key strings after v3

Unchanged from v2: 4 lessons · 40 quiz items (13 + 12 + 9 + 6) · 4 attached + 3 summary questions · 18 practice · bank 51 (47 four-option MCQs, 3 typed, 1 multi-select): EAR4-087 17 · 088 17 · 089 17; easy 20 / medium 20 / hard 11; bank MCQ keys A 13 · B 11 · C 12 · D 11; every quiz, practice and attached key string as in v2 (no option moved position; PP-19's new set keeps its key at the same letter).

#### Item ids changed in v3 (for the mini re-read)

Lesson quizzes: L01-02 (stem, fb, why) · L01-09 (name) · L02-02 (options A and C) · L02-07 (name) · L03-07 (name) · L04-05 (name). Bank: PP-07 (options, why) · PP-16 (option B, why) · PP-19 (options) · PP-28 (stem) · PP-30 (stem, why) · PP-31 (options A and B, why) · PP-32 (stem, why) · PP-34 (option A) · PP-35 (option C, why) · PP-45 (name) · PP-49 (option B, why) · PP-40 (blind text only). Lesson text, not items: L01's new granite line; L02's recall line; L03's headache, article and script (name). Records: TYPES_G4T28.md (v3 note, the exemplars for types 3, 4 and 8, inventory rows 30 and 32, the ⟂ list), grade4/NAMES_POOL.md (rows 28 and 23).

#### Judgement calls, v3

1. PP-28 is two sentences, not Reader C's three. The checker fails a three-sentence stem on a medium item (S23), and "Micah is wrong when he says…" carries the verdict in the same words.
2. Granite and sandstone are said in a lesson line rather than cut from the items. Both are Topic 19's rule words ("like sandstone or limestone"; "granite" in its drip scene), five items each lean on them, and one plain line in each article costs under ten words.
3. Charcoal is replaced, not taught. A lesson line on charcoal would have turned L01-02 from a transfer item into a recall of the line; "black blocks that burn in a barbecue grill" is what a nine-year-old sees.
4. PP-31 says "for a very long time" while L04's rule says "in our lifetimes". The coordinator's word ruling gives "in our lifetimes" to Topic 29; the L04 rule and lexicon were left as built, since changing a rule sentence changes the summary video's fifth beat. One line for the coordinator.

#### Owed after v3

• A mini re-read of the changed items above (blind/2026-10-02-v3/) by a reader who has not seen the keys.
• James's questions on the Needs-you page (records/REVIEW_NEXT_G4T28.md → course_preview/review/REVIEW_NEXT_G4T28.html); the picture pass (8 photo and 3 cartoon placeholders) waits on them.
• James's notes on the scripts are the cue to send the six-video batch.

Nothing committed.

Skill: course-build → write-mcqs → write-explanation, design-check-sequence @ efd8fba; v2 fix pass (the three reviews of 2 Oct 2026 applied) @ fb37d14; v3 polish (Reader C's full re-read applied) @ e23b67f

v3 (2 October 2026). The second girl is Joy (not Lara: Maria and Lara both end -ara). Shape tells trimmed or matched, keys unchanged: PP-07 (every option starts "They"), PP-16 ("a barrel of oil"), PP-19 (natural gas's own two-step set HOW_GAS), PP-34 ("a gas brought up a well from deep rock"), PP-35 ("It burns to heat the oven."), PP-49 ("a gas and a liquid"). PP-28's stem is two sentences. Plain words: PP-30 "a liquid fuel made from oil" (not jet fuel), PP-32 "Workers" (not drillers), PP-31 "for a very long time" (not in our lifetimes, Topic 29's phrase). New draw constraint: {#32, #44, PR-8} below.

v2 (2 October 2026). The second girl is Joy (not Mariana). Items re-scened or re-keyed in the fix pass: PP-07 (lure "They snap easily."), PP-12 (oil's own WHAT_OIL set), PP-14 (oil's own HOW_OIL set), PP-18 (a fresh stem: the fuel piped under the street with a blue flame), PP-21 (a new move: what a lump of coal does in a campfire — no blacksmith), PP-23 ("its heap is used up"), PP-24 ("gray rock", not shale), PP-31 (wells in California; key trimmed), PP-32 (a new move: the companion fuel drillers find above the oil), PP-34 (a hospital's water heater — no engine burns natural gas), PP-36 (key "It boils water into steam.", distractor "It cools the water."), PP-38 (wells in Wyoming; "run short"), PP-45 / 46 / 47 (one-clause keys), card T reworded ("a rock that burns / dug from the ground"). Lesson side: L03 split into L03 (natural gas) and L04 (the three-fuel capstone, six items: the liquid, the pipe, what nature keeps giving, Maria's TRUE claim, Joy's few-years claim, what all three started as). Key-tell checker: KEY TELLS: 0 of 107 MCQs flagged (a: 0, b: 0, c: 0).

Topic 28 — Fuels from under the ground — the PP100's question types, with their exemplars

What this page is. James reads a bank as its question TYPES first (vault: A bank is reviewed as its question types first, one exemplar each). Under the Grade 4 standing brief the bank is built straight away (51 items in content/G4T28_pp100_bank.py); this sheet is the way in. Each type line says what the stem asks, what the four options (or the accept list) are, and prints one exemplar in full. Tags follow depth of reasoning: easy = one fact or a one-step sort; medium = the rule applied to a fresh case, a reason picked, two facts chained, a card read; hard = a claim judged by its correct reason, a set answer, two topics chained, or a term produced. Difficulty rises with the atom's position: EAR4-087 (coal) 10 easy · 4 medium · 3 hard; EAR4-088 (oil) 6 · 8 · 3; EAR4-089 (natural gas) 4 · 8 · 5.

Rulings already applied. Four options on every MCQ, from four fixed sets rotated so the key moves (NAME4 "coal / oil / natural gas / gasoline"; WHAT4 "a black rock / a thick dark liquid / a gas you cannot see / a shiny metal"; FROM4 "plants of long-ago swamps / tiny living things of long-ago seas / melted rock from a volcano / sand pressed together"; HOW4 "dug out of a mine / pumped up a deep well / up a well and through long pipes / scooped from a lake"; SITS4 "in the tiny spaces of the rock / in a lake under the rock / mixed into the soil / in a big empty cave"). Hard items typed where typing produces (coal, fuel, oil); "natural gas", "power plant" and "gasoline" recalled by MCQ (RECALL_BY_MCQ: two-word terms, and the US child's everyday "gas"). One multi-select (the two fuels from the sea: the answer is a set). Every claim is "X is wrong. What is the correct reason?" with four single-statement reasons; no option bundles a verdict with its reason. Key letters A 13 · B 11 · C 12 · D 11. Every item is a fresh scene (see the inventory).

The bar list (real things a generated item must never use): "fossil fuel" (the register does not name it; Topic 29's), "renewable / nonrenewable" (Topic 29 coins them), any number of years ("a very long time" only), "petrol" (US: gasoline), "power station" (US: power plant), "refinery" ("a factory"), "turbine" ("a big wheel"), "propane" or a camp stove (propane is neither fuel taught), charcoal as a fuel from under the ground (it is made from wood), dinosaurs as the source of any fuel (the belief, never a key), a gas leak or any safety rider, a frightening scene (a mine collapse, a fire), any person or hand drawn as a glyph.

The eleven types (fewer would be better; three fact atoms each need what-is, where-from and what-for, so the count is what it is)

Hard because — type 11: the word is produced from its origin, with no description of its look; the coined term from its definition over three members; natural gas recalled from its whole description with no clue word; the multi-select's answer is a set. Type 9: each claim is judged by its correct reason, which needs the lesson's idea held against the belief (the sponge against the lake; the well and pipes against the gas station; burning against "just air"). Type 7 hard: two fuels traced back at once, one through the factory step; a Grade 3 fact chained with this topic's. Type 6 hard: Topic 21's order of layers chained with coal's origin.

One exemplar per type, in full

Type 1 (easy, EAR4-087). Miners in West Virginia bring up a black rock that burns. Which fuel is it? — gasoline / coal / oil / natural gas. Why: Coal is a black rock that burns. People dig coal out of the ground in mines. So the black rock is coal. (nearest lesson-side instance: L01-q12, "a black rock that burns is dug out of a mine in Kentucky… what is the rock called?", three options — here the set is the four fuel names)

Type 2 (easy, EAR4-087). A thick black layer of coal runs through a hillside in Illinois. What did that coal start as, a very long time ago? — plants of long-ago swamps / tiny living things of long-ago seas / melted rock from a volcano / sand pressed together. (nearest: L01-q6, "what did coal start as", three options; here the sea distractor is added and the scene is a layer in a hillside)

Type 3 (medium, EAR4-087). A coal power plant in Utah gets no coal for a week, and its heap is used up. What happens to the electricity it makes? — The plant stops making electricity. / The plant makes electricity as before. / The plant makes more electricity. / The plant makes gasoline instead. Why: A power plant burns coal to boil water into steam, and the steam pushes the big wheel that turns a machine that makes electricity. With no coal, nothing burns and no steam forms. So the plant stops making electricity. (nearest: L01's power-plant lines and PR-9's first-step item; no lesson item removes the coal)

Type 4 (easy, EAR4-087). A camper in Oregon burns dry sticks to cook supper. What is the correct reason the sticks are a fuel? — They give out heat when they burn. / They are brown all the way through. / They are dry and light to carry. / They snap in half very easily. (nearest: L01-q2 charcoal yes/no; here the reason is picked)

Type 5 (medium, EAR4-088). Deep under Illinois, layer J is granite with no spaces between its grains, and layer K is sandstone with tiny spaces between its grains. Which layer could hold oil? — layer K / layer J / both layers / neither layer. Leans on EAR4-006 (Topic 19). (nearest: L02-q4, where in the rock the oil is; here two layers are compared)

Type 6 (medium, EAR4-087). A cliff in Alabama shows these layers, from the top down: sandstone, gray rock, a black layer of coal, more gray rock. What was the place like when the coal layer formed? — a desert of sand / a swamp full of plants / a warm sea / a volcano. Leans on EAR4-038 (Topic 21). (nearest: none on the lesson side; the move is Topic 21's read-the-story applied to coal)

Type 7 (medium, EAR4-089). A van burns "gas" from a gas station, and a water heater burns "gas" from a pipe under the street. Which fuel does the water heater burn? — natural gas / gasoline / coal / oil. (nearest: L03-q4, what goes into the school bus's tank, two options; here both "gases" sit in one stem and the heater is asked)

Type 8 (medium, EAR4-088). Wells in California have pumped oil from the rock under a field for a hundred years, and now they bring up very little. Which of these is true? — New oil forms in that rock every single year. / Nature will not make more oil for a very long time. / The oil has turned into coal. / The oil has turned into sand. (nearest: L03-q10, Joy's claim about natural gas in a few years, yes/no; here the fuel is oil and the statement is picked)

Type 9 (hard, EAR4-088). Joy says the oil under a field lies in a big underground lake. Joy is wrong. What is the correct reason? — Oil floats on water. / The oil is too thick to make a lake. / The oil sits in the tiny spaces of the rock. / The oil is too dark to see. (nearest: L02-q6, Maria's lake claim, bare yes/no; here the reason is the target)

Type 10 (medium, EAR4-089). [drawing pp_cards_jkn: card J "a thick dark liquid / pumped up a deep well"; card K "a black rock / dug out of a mine"; card N "a gas you cannot see / sent through pipes"] Here are three cards, J, K and N, each describing a fuel. Which card describes natural gas? — card J / card K / card N / none of the cards. (nearest: L03-q1, which fuel is the thick dark liquid; here three descriptions sit on cards and one is matched)

Type 11 (hard, EAR4-087, typed). A fuel formed from plants of long-ago swamps, pressed for a very long time, and people dig it out of mines. Type the name of the fuel. — accept: coal, coals, cole, coel, kole, a coal, the coal. Wrong-answer lines for "oil" and "wood". (nearest: L01-q13, the typed coal item from a train and a power plant; here the stem is the origin alone)

The design-move inventory (every bank item: move · scene kind · nearest earlier item)

Freshness is judged on the template, not the nouns. Lesson-side instances inventoried: L01 (cabin stove; log / coal / sunlight cards; the swamp strip; the power plant steps; quiz: Vermont logs, charcoal grill, Arizona solar panel, "what is coal", Ohio power plant, "what did coal start as", granite does not burn, Micah's always-there claim, Joy's power-plant-makes-coal claim, candle wax, "a thing people burn", a Kentucky mine, typed coal from a train); L02 (gas station and nodding pump; the oil jar; Topic 19's lens; the sea strip; the well → factory → car steps; quiz: plastic bucket, sandstone drop, "what is oil", North Dakota rock, "what did oil start as", Maria's lake, Joy's sponge, Micah's dinosaurs, gasoline recognition, Florida bus, which came first, typed oil from an Alaska well); L03 (pancakes and the blue flame; the gasoline table; the oil-and-gas strip; the pipes steps; the three-fuel table; quiz: the three names, "what is natural gas", which thing burns it, the Georgia bus's tank, "what did it start as", where it is found, Maria's same-things claim, Micah's gas-at-the-pump claim, Nevada power plant, Joy's few-years claim, Kansas pipes); attached (Wyoming train; Oklahoma truck; Michigan school furnace; Kentucky museum; Louisiana well; New York pizza oven); practice (wooden chair; Maine leaf; the lake running short; sandstone or granite; a big ship to Washington; which fuel from plants; Idaho pool heater; Nebraska oil and gas; Virginia first step; Kentucky hillside FRQ; Maria's gas-station claim; Micah's wind-and-sunlight claim; Tennessee power plant; fuels; Iowa hotel; typed fuel, coal, Utah oil).

⟂ draw constraints (an item that prints another's answer; near-twins): {#3, #10, PR-6} (plants ↔ coal); {#13, #37, #48, #43} (sea things ↔ oil / natural gas); {#19, #46} (PP-46's key, up a well from deep rock, is half of PP-19's); {#45, L02-q6} (the lake, judged twice); {#46, L03-q7 old / PR-11} (made at the station); {#6, #16}; {#18, #20}; {#27, #30}; {#24, #29}; {#33, #46} (gas station "gas"); {#31, #38}; {#32, #44, PR-8} (PP-44's stem and PR-8's stem both say the gas sits above the oil, which is PP-32's answer — Reader C, v3). The test builder draws one per test from each set.

Skill: course-build → review-lesson (Roles B, B2) · review-questions · review-accuracy @ 69d9899 — non-author review, filed by the coordinator from the reviewer's report

Topic 28 — guidance, questions and accuracy review, 2 October 2026

The science is sound at Grade 4 depth and the teaching shape is right: each fuel gets what-it-is → where-from (a four-panel strip) → what-we-burn-it-for; the "fuel" coin is earned by a three-card run with sunlight as the honest near-miss; the dinosaur, lake, made-at-the-station and "nature makes more soon" beliefs are each met by a lesson line and an item; nothing frightens or dates a shortage. Three things must change: the key-tell gate (10 flags, 7 real); the power-station chain says "the wheel makes electricity" where Topic 27 says the wheel turns a machine that makes electricity; two TRUE-claim items (L02-q7, L03-q7) are the previous item's feedback read back. Re-performed: scripts 147/147/147, intro 120, summary 150; articles 365/374/418 (runs 4/5/4); bank 51 (17/17/17), keys A13 B11 C12 D11.

Coordinator's rulings (applied without asking James): "energy resource" is the course word (Topic 27 coins it; Topic 28 changes its three "energy source" strings). "Power plant" is coined HERE (US word); Topic 27 describes without naming; Topic 29 says "power plant". Deep time: Topic 28 keeps "a very long time"; Topic 29 reveals "That very long time was millions of years." "Fossil fuel": not here; Topic 29's nonrenewable lesson names it once, recognition only (NGSS 4-ESS3-1 and STAAR use it). Coal's origin phrase aligned to Topic 28's "plants of long-ago swamps, buried and pressed" in Topic 29; oil/gas "tiny sea living things" everywhere.

Key-tell checker: KEY TELLS: 10 of 102 MCQs flagged (a: 9, b: 1, c: 0) — 7 real + PR-2; PR-8 / summary-Q2 are the from-set (shorten "tiny living things in the sea" to "tiny sea living things" everywhere, or declare the set).

Author's questions: (1) fossil fuel — not here (ruling above). (2) "fuel" coined in L01 — yes, load-bearing for Topic 29. (3) L02's shorter rule — right. (4) Maria/Mariana — change Mariana. (5) articles — L01, L02 stand; L03 (418) splits at "Three fuels from under the ground" into a ~90-word capstone article with L03-q1 as the check between.

Essentials

1. Power-station chain disagrees with Topic 27 (L01 article, step-row chip, PR-9 option, PP-5/23 why, L03-q9 fb).
2. Key tells: L03-q3, L03-q6, PP-31, PP-36, PP-45, PP-46, PP-47, PR-2; the from-set phrase.
3. L02-q7 and L03-q7 handed over by the previous item's feedback and the lesson line in the stem.

Worth fixing

L01-q10 candle (burned for light; "no" defensible). "Power plant" never explained in the L01 video. L03-q2 and PP-18: "natural gas" in the stem hands over "a gas". PP-47's belief ("natural gas is just air") has no lesson line. PP-36 distractor "blows on the wheel" is true of a gas turbine. "runs out" vs Grade 3's "runs short". Maria/Mariana.

Leave

"Most coal goes to a power plant" (EIA ~90%, note the source). "Coal burns because it was once plants." PP-48/49 answerable from atom 089's rule. Attached keys B A B A B A (sets differ). Fixed sets exempt. Named simplifications accurate.

Topic 28 / 29 / 27 disagreements (owed to the named topic)

1. Deep time — T29 reveals "That very long time was millions of years." (T29 fix pass). 2. Power plant — T27 describes without naming; T29 says "power plant" (T27, T29 fix passes). 3. Coal's origin — T29 aligns to "plants of long-ago swamps, buried and pressed" (T29). 4. Oil/gas origin — "tiny sea living things" (both). 5. "Nature keeps giving" — T29 echoes once (T29, optional). 6. The chain — T28 (this pass). 7. "Fuel" — T28's coin stands.

Skill: review-figures @ 69d9899 — non-author figure review with the page pass, filed by the coordinator from the reviewer's report

Topic 28 — figure review, 2 October 2026

What a student notices first: the three story strips — four square panels left to right, one arrow size, chips under each; swamp → mud → pressed → coal reads at a glance; the oil/gas strip's last panel shows the gas band above the oil. Burning is a flame, never smoke. On a phone almost every drawn figure is a postage stamp: 560-unit frames at 278 px give 5 px chips, cells and card text.

Fix before the cold read

1. pp_cards_jkn, pp_cards_prt — the only item figures; card text ≈ 5.5 px at 360 px (asked datum must read ≥ 13 px). Fix in cards_row: stack the three cards in a ~320-wide frame (or two rows) with 14–16 px text.
2. power_plant_steps — no carrier chip on any arrow where Topic 27 taught the same shape with HEAT / PUSH / ELECTRICITY chips; the flame floats beside the coal lump. Redraw with Topic 27's source_card (imported): coal burning —HEAT→ water in pipes —PUSH→ the big wheel —ELECTRICITY→ homes; flame rising from the lump.
3. strip_coal — panel 4's coal layer is three times thicker than panel 3's pressed band (coal grows after pressing). Equal thickness, or caption as a close-up.
4. gas_to_stove_steps — the wire's baseline and posts sit on the "A POWER PLANT" chip. Lift the icon 8 units or drop the wire.

Page pass

Desktop: every figure renders as alone; no broken images; 11/8/8 SVGs per article. Phone: item cards FAIL (1); the four tables and three rule cards illegible; rule cards duplicate the rule box above them — drop rule_* from the articles (keep for video); split table_fuels_three / table_gas_vs_gasoline for phone as Topic 26 did. check_svg_ids: 30 figures, 0 ids, PASS.

Unplaced

rule_fuel — place under L01's coin line or delete.

Minor

_factory roof polyline ends in the air; _well reads as a tent; strip_oil band tan vs Topic 19's cream limestone on the same page (match); oil_in_spaces says "limestone" (recall, fine); sunlight card's wall could read as a window; strip_oil_gas 9 px in-panel labels. Captions never say "real"; alt counts match; placeholder briefs complete, nothing frightening.

Best: strip_oil_gas; the fuel_cards pair; table_fuels_three. Weakest: power_plant_steps; pp_cards at phone width; strip_coal panel 4.

Skill: course-build → review-lesson (Role A blind key read, two readers; Role C adjudication by the coordinator) @ fb37d14

Topic 28 — Fuels from under the ground — blind read, 2 October 2026

Three wrong keys caught and fixed before anything else moved. Both readers, independently, answered PP-12 "a thick dark liquid" (keyed "a black rock"), and PP-13 and PP-37 "tiny living things of long-ago seas" (keyed "plants of long-ago swamps"). The readers were right: oil is the liquid, and oil and gas began as tiny sea living things. Cause: the bank's _rot(list, k) helper keys the list's FIRST member; three oil items rotated WHAT4 / FROM4 without putting the oil member first. Fixed in G4T28_pp100_bank.py (the oil member rotated to the front, as the author already did for HOW4 and NAME4); every other key's text checked against its why line by script. Otherwise 106 of 111 items agreed by both readers; the two typed off-list rows are accept-list widenings; PP-48 multi A, B matched; PR-10's FRQ models match the key's four points. The intro poll is not bundled by design.

Flags carried into the fix pass

Readers' files: blind/2026-10-02/READER_A.md, READER_B.md.

Skill: review-lesson @ e23b67f — Role A (blind key reader), Reader C, cold read of BLIND_BUNDLE_G4T28.md (v2) only.

Takeaway

Every item in the v2 bundle has exactly one true option; I found no second-defensible option and no oil item whose distractor is itself true. The coal / oil / natural-gas origin story is told the same way in every item (swamp plants → coal; tiny sea living things → oil and gas), so the bank is consistent. What remains is shape: three PP items let a child pick the key by its look alone (PP-07 the only option not starting "They", PP-16 the only bare noun among "a …" options, PP-35 the only option with "and"), and three more have a milder length or comma tell (PP-19, PP-34, PP-49). One in-bank giveaway: PP-44's stem says gas sits "often above the oil", which answers PP-32. Names: Maria and Lara are the closest pair (both end "-ara"); never answer-bearing, but one swap would remove the risk.

Items

Adversarial answers (typed items)

Cross-item notes

• Every oil item has one true option; the three oil claims the brief named (thick dark liquid pumped up a well; tiny sea living things; coal from swamp plants) are stated identically in L02, L04, SUMMARY, PR and PP. No contradictions.
• Yes/No strings: L01 yes-no-no-no-yes; L02 no-yes-no; L03 yes-no; L04 yes-no-no; PR no-no; PP-45/46/47 all "X is wrong" with a reason — fine.
• Giveaway: PP-44 and PR-08 state that gas sits above the oil, the fact PP-32 tests.
• Shape tells: PP-07, PP-16, PP-35 (hard); PP-19, PP-34, PP-49, L02-02 (soft).
• Unmet terms (all carried by their scene): charcoal, granite, sandstone, furnace, drillers, jet fuel, "in our lifetimes".
• Re-scening oddities: PP-28 ("but he is wrong about the oil"), PP-40 card R comma.
• Names: Maria / Lara share the "-ara" ending and sit in the same quizzes (L01, L02, L04, PR); Micah is distinct. Swap Lara for a name with a different shape (e.g. Ben, Noah). Never answer-bearing.

Would not ship as is: PP-07, PP-16, PP-35 (shape tells); PP-32 until a draw constraint with PP-44 is recorded.