Volcanoes: how and where

Tests: 7 of 10 right · Exam: 3 of 4 right · Kind: plain · Understood: 9 of 14 · Run: 2026-10-18, commit f3c23ea72

Lesson 46 of the geography course of Mova's primary school, as Mova's small model took its tests: it had read this lesson and the ones before it and learned from their exercises. Each test shows the options in the order the student saw them, its choice, the right answer, the score of every option and why it chose. The lesson itself, sentence by sentence with trees and pragmatics: the lesson in the corpora.

Every question of this lesson and each of its options parsed by Mova, with trees and pragmatics: the lesson's questions in the corpora.

Test 1 · right ✓

Ben says: "Lava and magma are two different kinds of rock." Put him right.

1. It's the same melted rock: magma underground, lava on the surface — ← Mova's choice · ✓ the right answer · no support
2. Magma is ash and lava is gas — no support
3. He's right, magma is solid rock and lava is the liquid kind that flows — no support
4. Lava is the one underground and magma is the one on top — no support

Why: No option found support in what it remembers, so it guessed: it took the first option shown. · the question and its options parsed, with trees and pragmatics

Test 2 · right ✓

In a game, a character outruns a pyroclastic flow on foot. What's wrong?

1. They only ever move uphill, never down — no support
2. They are made of cool water — no support
3. Nothing, they move at walking pace, so anyone fit can get away — no support
4. Pyroclastic flows race at over 100 km/h, far faster than a runner — ← Mova's choice · ✓ the right answer · score 5

Why: It took the question to ask which statement is true. It chose option 4 with score 5, the only option with support. Its support: lesson 46, line 13: «The deadliest danger is a pyroclastic flow, an avalanche of hot gas, ash and rock racing downhill at over 100 km/h.», reached through the same lesson line as the sentence the question matched. What matched: the same action «race» (+3); the same place «100 km/h» (+3). Against it: a different doer (counts against) (-1). · the question and its options parsed, with trees and pragmatics

Test 3 · wrong ✗

"how come hawaii has volcanoes, it's not on a plate edge??"

1. It is right on the edge of the Pacific plate, where it meets Asia — no support
2. It sits over a hotspot, hot rock rising from the deep mantle — ✓ the right answer · score 3
3. Its volcanoes are made by the strong tides — ← Mova's choice · score 8
4. It doesn't have any volcanoes really, just hills — no support

Why: It took the question to ask which statement is true. It chose option 3 with score 8, against 3 for the next best. Its support: lesson 42, line 4: «What happens at a plate's edge depends on how the plates meet: pulling apart makes new sea floor, one diving under another makes trenches and volcanoes, two co…», reached through the remembered sentence the question matched. What matched: the same thing acted on «trenches» (+5); the same action «make» (+3). The right option, 2, scored 3. · the question and its options parsed, with trees and pragmatics

Test 4 · right ✓

The Hawaiian island of Kauai is old and worn, while Big Island still erupts. Why?

1. The hotspot moves around the Pacific each year — no support
2. The plate carried Kauai away from the hotspot long ago — ← Mova's choice · ✓ the right answer · score 4
3. Kauai was built by a different kind of volcano — no support
4. Kauai is closer to the hotspot than Big Island is, so it cooled first — no support

Why: It took the question to ask why something happens (its cause). It chose option 2 with score 4, the only option with support. Its support: lesson 46, line 10: «As the plate slides over a hotspot, a chain of volcanoes forms, and the Hawaiian islands get older the further they are from the hotspot.», reached through the same lesson line as the sentence the question matched. What matched: the same doer «plates» (+2); the same place «hotspot» (+2). · the question and its options parsed, with trees and pragmatics

Test 5 · right ✓

Mia reckons most volcanic eruptions happen on mountains we can see. What's true?

1. Most happen unseen on the ocean floor along ridges — ← Mova's choice · ✓ the right answer · score 13
2. Most happen high in the Alps — score 3
3. All of them are on land, where people can see and count them — no support
4. Most happen in Britain's mountains — score 3

Why: It took the question to ask which statement is true. It chose option 1 with score 13, against 3 for the next best. Its support: lesson 46, line 5: «Most volcanic activity happens unseen on the ocean floor, along the mid-ocean ridges where new crust is made.», reached through the remembered sentence the question matched. What matched: the same place «ocean floor» (+4); the same circumstance (+4); the same action «happen» (+3); the same property (+2). · the question and its options parsed, with trees and pragmatics

Test 6 · right ✓

What would happen if a huge eruption emptied a volcano's magma chamber?

1. Nothing, the chamber stays empty and holds up — no support
2. The volcano would turn into a lake of lava for ever — no support
3. The volcano would grow twice as tall — no support
4. The ground above could collapse into a caldera — ← Mova's choice · ✓ the right answer · score 8

Why: It took the question to ask what happens next. It chose option 4 with score 8, the only option with support. Its support: lesson 46, line 17: «When a huge eruption empties the magma chamber, the ground above can collapse into a giant crater called a caldera.», reached through what followed the sentence the question matched. What matched: the same action «collapse» (+4); the same doer «ground» (+4). · the question and its options parsed, with trees and pragmatics

Test 7 · right ✓

A wide, gently sloping volcano pours out runny lava that flows for kilometres. What type is it?

1. A hotspot ridge cone — no support
2. A shield volcano — ← Mova's choice · ✓ the right answer · score 12
3. A stratovolcano — no support
4. A caldera — no support

Why: It took the question to ask who or what does it. It chose option 2 with score 12, the only option with support. Its support: lesson 46, line 7: «Melted rock is called magma while it is underground and lava once it pours out on the surface.», reached through the same lesson line as the sentence the question matched. What matched: it fills the role the question asks for (+5); the same doer «volcano» (+4); the same light verb (be, have, do, get, go) (+3). · the question and its options parsed, with trees and pragmatics

Test 8 · wrong ✗

A volcano hasn't erupted for 2,000 years. Tom says: "It's extinct, totally safe." Right?

1. Yes, volcanoes only ever erupt once — score 2
2. Yes, 2,000 years means it is extinct — no support
3. No, it will certainly erupt next year — ← Mova's choice · score 3
4. No, it counts as active and could erupt again — ✓ the right answer · score 2

Why: It took the question to ask which statement is true. It chose option 3 with score 3, against 2 for the next best. Its support: lesson 46, line 16: «A volcano is usually called active if it has erupted in about the last 10,000 years, and extinct if it is not expected to erupt again.», reached through the option's own match among the sentences about the question's things. What matched: the same doer «volcano» (+3); the same action «erupt» (+2); the same property (+1). Against it: one says «not», the other does not (counts against) (-3). The right option, 4, scored 2. · the question and its options parsed, with trees and pragmatics

Test 9 · wrong ✗

"the volcano stinks like rotten eggs, what is that"

1. Rotting trees buried under the ash — ← Mova's choice · no support
2. The smell of the hot rocks only — no support
3. Lava burning old food in the crater — no support
4. Sulfur gases from the volcano — ✓ the right answer · no support

Why: No option found support in what it remembers, so it guessed: it took the first option shown. · the question and its options parsed, with trees and pragmatics

Test 10 · right ✓

A steep, cone-shaped volcano made of layers of ash and lava sits above a subduction zone. What is it most likely to do?

1. Erupt explosively from time to time — ← Mova's choice · ✓ the right answer · no support
2. Never erupt again — no support
3. Pour out only gentle runny lava for ever — no support
4. Erupt only deep under the sea — no support

Why: No option found support in what it remembers, so it guessed: it took the first option shown. · the question and its options parsed, with trees and pragmatics

Exam question 1 · formal language · right ✓

Which of the following statements most accurately characterises the distinction between magma and lava?

1. Magma denotes molten rock beneath the surface; lava denotes the same material once erupted — ← Mova's choice · ✓ the right answer · score 0
2. Magma denotes solid rock; lava denotes molten rock beneath the surface — score 0
3. The terms are applied to rocks of wholly different chemical composition and origin — no support
4. Magma denotes volcanic ash; lava denotes the gas emitted during an eruption — score 0

Why: It took the question to ask who or what does it. It chose option 1 with score 0, tied with another option at 0 (the first shown, or the one claiming less beyond what it knows, wins). Its support: lesson 42, line 9: «Where plates move apart, magma rises to fill the gap and makes new crust, as along the Mid-Atlantic Ridge.», reached through the remembered sentence the question matched. What matched: it fills the role the question asks for (+2). Against it: a different action (counts against) (-2). · the question and its options parsed, with trees and pragmatics

Exam question 2 · formal language · right ✓

Identify the principal location of the majority of the Earth's volcanoes.

1. Along the boundaries of the lithospheric plates — ← Mova's choice · ✓ the right answer · no support
2. Exclusively within the polar regions — no support
3. Within the interior of the continents far from any boundary — no support
4. Exclusively along the equator — no support

Why: No option found support in what it remembers, so it guessed: it took the first option shown. · the question and its options parsed, with trees and pragmatics

Exam question 3 · formal language · wrong ✗

Select the response that is consistent with the established facts concerning a pyroclastic flow.

1. A slow stream of basaltic lava advancing at walking pace — ← Mova's choice · no support
2. A sudden discharge of cold water from a crater lake upon the slopes of the volcano situated below — no support
3. A current of hot gas, ash and rock descending at velocities exceeding one hundred kilometres per hour — ✓ the right answer · no support
4. An emission of steam from a hot spring — no support

Why: No option found support in what it remembers, so it guessed: it took the first option shown. · the question and its options parsed, with trees and pragmatics

Exam question 4 · formal language · right ✓

It is given that the magma chamber of a volcano has been evacuated by a major eruption. Ascertain the probable consequence for the overlying ground.

1. Its elevation to form a new stratovolcano — no support
2. Its separation from the plate as a hotspot — no support
3. Its conversion to a mid-ocean ridge — no support
4. Its collapse to form a caldera — ← Mova's choice · ✓ the right answer · score 5

Why: It took the question to ask which statement is true. It chose option 4 with score 5, the only option with support. Its support: lesson 46, line 17: «When a huge eruption empties the magma chamber, the ground above can collapse into a giant crater called a caldera.», reached through the option's own match among the sentences about the question's things. What matched: the same doer «ground» (+3); the same action «collapse» (+2). · the question and its options parsed, with trees and pragmatics

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