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)
| Type | Items | Atom | Tags | Form | The stem asks… | The options / the accept | Exemplar scenes |
|---|---|---|---|---|---|---|---|
| 1 | 9 | all | easy, medium | MCQ, NAME4 or WHAT4 | which fuel fits a clue (what it is, how it is got out); which description fits a named fuel | coal / oil / natural gas / gasoline; a black rock / a thick dark liquid / a gas you cannot see / a shiny metal | West Virginia miners; a Montana well; a Colorado well; the fuel trapped above the oil |
| 2 | 8 | all | easy, medium | MCQ, FROM4 or a reason set | what a fuel started as; what the pressed swamp plants became; which fuel formed from plants; why coal burns; why oil lies under dry land; what oil and gas both started as | plants of long-ago swamps / tiny sea living things / melted rock / pressed sand; four single statements | an Illinois coal layer; New Mexico; a Tennessee blacksmith; the Gulf of Mexico |
| 3 | 7 | 087, 088, 089 | easy, medium | MCQ | what a power plant makes; where a boat of coal is going; what the factory makes from oil; what the burning fuel does to the water; what happens when the coal runs out; what the gas does in a glass oven | four things / four events | Indiana; the Mississippi River; New Jersey; Missouri; Utah; a glass factory; Massachusetts |
| 4 | 4 | 087, 088 | easy | MCQ | which of four things is a fuel; why the sticks are a fuel | one burned thing and three not; four reasons | a lump of coal among water, sand, a spoon; an Oregon camper |
| 5 | 6 | all | easy, medium | MCQ, HOW4 or SITS4 | how a fuel is got out; where oil sits (lettered layers J / K); where the factory's oil comes from | dug / pumped / piped / scooped; the tiny spaces / a lake / the soil / a cave | three how-out items; Illinois layers J and K; Micah's factory |
| 6 | 3 | 087, 088 | medium, hard | MCQ | what the place was like when a layer formed; which happened first in a cliff | a swamp / a sea / a desert / a mountain; four events | an Alabama cliff; Mississippi rock; a Colorado cliff (hard: two topics chained) |
| 7 | 7 | 088, 089 | medium, hard | MCQ, NAME4 or statements | trace a machine or product back to its fuel: a lawn mower, an airplane's liquid fuel, a van against a water heater, a garbage truck, a furnace and a car, a plastic toy and gasoline | the fuel names; where it was; what the two were when they came out | Iowa; an airplane; Washington; Minnesota (hard); plastic and gasoline (hard) |
| 8 | 2 | 088, 089 | medium | MCQ | what is true of a field pumped for a hundred years; what happens to the gas in a rock as the wells bring up less | four statements / four events | California; Utah |
| 9 | 3 | 088, 089 | hard | MCQ | a named child's claim is wrong: what is the correct reason (the lake; made at the gas station; natural gas is just air — L03 now says "Natural gas is not air. Air does not burn.") | four single-statement reasons | Joy's lake; Micah's gas station; Maria's air |
| 10 | 2 | 088, 089 | medium | MCQ, drawn lettered cards | which card describes natural gas / oil | card J / K / N / none; card P / R / T / none | the two card rows (letters outside A–D; stems and drawings from one list) |
| 11 | 5 | all | hard | typed; MCQ on the whole definition; multi-select | type the fuel from its origin (coal, oil); type the word for a thing burned for heat (fuel); the term from its whole description (natural gas); which TWO fuels formed in the sea | COAL_T, FUEL_T, OIL_T accept lists; NAME4; coal / oil / natural gas / wood | no scene (the definition is the stem); the multi-select |
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).
| # | d | Atom | T | Move (what the student does with what) | Scene kind | Nearest earlier item |
|---|---|---|---|---|---|---|
| 1 | easy | 087 | 1 | names the fuel from "black rock that burns, brought up by miners" | miners, West Virginia | L01-q12 (three options, a mine) — shared fact, four-name set |
| 2 | easy | 087 | 1 | picks coal's description among four | none | L01-q4 (three options) — shared fact, four-thing set |
| 3 | easy | 087 | 2 | names coal's origin from a layer in a hillside | a coal layer, Illinois | L01-q6 — shared fact, new sea distractor |
| 4 | easy | 087 | 2 | predicts what pressed swamp plants became | the swamp story as a prediction | strip_coal (teaching); no lesson item asks the end product |
| 5 | easy | 087 | 3 | names what a coal power plant makes | Indiana power plant | L01 lines; L01-q5 names the building — new ask |
| 6 | easy | 087 | 4 | picks the one fuel among four things | none | L01's fuel cards (teaching) |
| 7 | easy | 087 | 4 | picks the reason sticks are a fuel | an Oregon camper | L01-q2 charcoal (yes/no) — reason form is new |
| 8 | easy | 087 | 5 | names how coal is got out | none | L01 line "dig coal out of the ground in a mine" |
| 9 | easy | 087 | 3 | infers where a load of coal is going | a flat boat on the Mississippi | NEW |
| 10 | easy | 087 | 2 | picks the fuel that formed from plants | none | PR-6 (three options) — ⟂ draw constraint with PR-6 and #3 |
| 11 | easy | 088 | 1 | names the fuel from "thick dark liquid up a well" | a Montana well | L03-q1 (three options) — shared fact |
| 12 | easy | 088 | 1 | picks oil's description | none | L02-q3 — shared fact, four-thing set |
| 13 | easy | 088 | 2 | names oil's origin | New Mexico rock | L02-q5 — shared fact |
| 14 | easy | 088 | 5 | names how oil is got out | none | L02 line |
| 15 | easy | 088 | 3 | names what the factory makes from oil | New Jersey factory | L02-q9 — shared fact |
| 16 | easy | 088 | 4 | picks the one fuel (oil) among four | none | #6 (same move, different member; draw one per test) |
| 17 | easy | 089 | 1 | names the fuel from "a gas up a well into pipes" | Colorado well | L03-q11 — shared fact |
| 18 | easy | 089 | 1 | picks natural gas's description | none | L03-q2 — shared fact |
| 19 | easy | 089 | 5 | names how natural gas reaches a home | none | L03 lines |
| 20 | easy | 089 | 1 | picks the fuel that is a gas | none | #18 (same fact asked the other way; draw one per test) |
| 21 | medium | 087 | 2 | predicts what a lump of coal does in a campfire | a Wisconsin camper's fire | L01-q4 (what coal is) — the prediction form is NEW (v2; the blacksmith reason item repeated L01-q7) |
| 22 | medium | 087 | 3 | says what the heat does to the water | Missouri power plant | L01 lines; PR-9 orders the steps — new ask |
| 23 | medium | 087 | 3 | predicts the effect of no coal | Utah power plant's heap runs out | NEW |
| 24 | medium | 087 | 6 | reads the long-ago place from a coal layer in a cliff | an Alabama cliff | NEW (Topic 21's move on coal) |
| 25 | medium | 088 | 5 | compares two lettered layers for holding oil | layers J and K under Illinois | PR-4 (sandstone or granite, Topic 19 recall) — shared move, lettered pair |
| 26 | medium | 088 | 2 | picks the reason oil lies under dry land | New Mexico | NEW |
| 27 | medium | 088 | 7 | traces a mower's gasoline back to oil | an Iowa lawn mower | L02-q10 (Florida bus) — shared chain, machine changed; draw one per test with #30 |
| 28 | medium | 088 | 5 | corrects "made out of nothing": where the factory's oil comes from | Micah's claim | PR-11 Maria's gas-station claim — different fuel step (oil, not gasoline) |
| 29 | medium | 088 | 6 | reads the long-ago place from oil-bearing rock | Mississippi | #24's move on oil (draw one per test) |
| 30 | medium | 088 | 7 | traces an airplane's liquid fuel back to where the oil sat | an airplane | #27 — same chain, the ask is where the oil sat |
| 31 | medium | 088 | 8 | judges what is true of rock pumped for oil for a hundred years | California wells | L03-q10 (natural gas, yes/no) — statement form |
| 32 | medium | 089 | 1 | predicts the companion fuel the workers find above the oil | Kansas well workers | L03-q6 — shared fact, prediction form (v2; the old stem was #44's description) |
| 33 | medium | 089 | 7 | tells the heater's "gas" from the van's | a van and a water heater | L03-q4, L03-q8 — shared confusion, both in one stem |
| 34 | medium | 089 | 7 | traces a water heater's natural gas to its source | a Washington hospital | #19 (how it reaches a home) — shared fact, vehicle scene |
| 35 | medium | 089 | 3 | says what the gas does in a glass oven | a glass factory | NEW |
| 36 | medium | 089 | 3 | says what the burning gas does in a power plant | Massachusetts | L03-q9 — shared fact, the step named |
| 37 | medium | 089 | 2 | names what oil and gas both started as | the Gulf of Mexico sea floor | PR-8 (Nebraska) — shared fact; ⟂ #48 |
| 38 | medium | 089 | 8 | predicts the fate of the gas in long-pumped rock | Wyoming wells | L03-q10 — shared idea, prediction form |
| 39 | medium | 089 | 10 | matches a card to natural gas | cards J K N | NEW form |
| 40 | medium | 088 | 10 | matches a card to oil | cards P R T | NEW form |
| 41 | hard | 087 | 11 | types coal from its origin | none | L01-q13 typed coal (a train) — the stem is the origin |
| 42 | hard | 087 | 11 | types "fuel" from its definition | none | PR-16 typed fuel (camper and power plant) |
| 43 | hard | 088 | 11 | types oil from its origin | none | L02-q12 typed oil (an Alaska well) |
| 44 | hard | 089 | 11 | recalls "natural gas" from its whole description | none | L03-q11 — no clue word here |
| 45 | hard | 088 | 9 | picks the reason the lake claim is wrong | Joy's lake | L02-q6 Maria's lake (yes/no) |
| 46 | hard | 089 | 9 | picks the reason the gas-station claim is wrong | Micah's gas station | L03-q7 (yes/no) and PR-11 |
| 47 | hard | 089 | 9 | picks the reason "just air" is wrong | Maria's air | NEW belief (a look-alike) |
| 48 | hard | 089 | 11 | selects the two sea fuels | none | #37, PR-8 — ⟂ |
| 49 | hard | 089 | 7 | traces two household fuels back at once | a Minnesota furnace and car | NEW |
| 50 | hard | 087 | 6 | orders a coal layer's story under sandstone | a Colorado cliff | PR-10 FRQ (how coal formed) — the order step is new |
| 51 | hard | 088 | 7 | finds the one source of plastic and gasoline | none | L02-q1 (plastic bucket, Grade 3) chained with L02-q9 |
⟂ 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.