Inside the Earth

Tests: 2 of 11 right · Exam: 2 of 4 right · Kind: plain · Understood: 5 of 15 · Run: 2026-10-18, commit f3c23ea72

Lesson 41 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 · wrong ✗

Jack says: "Under the ground it's all lava, like a giant soup, that's why volcanoes happen." Put him right.

1. Under the ground it's all solid iron — ← Mova's choice · no support
2. Under the ground is a big empty cave — no support
3. He's right, the whole inside of the Earth is runny lava, all the way down to the centre — no support
4. The mantle is solid rock that flows very slowly; only small pockets melt — ✓ 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 2 · wrong ✗

In a cartoon, two kids dig a hole in their garden all the way through to Australia. What's wrong with it?

1. The hole would fill with seawater at once — ← Mova's choice · no support
2. The crust alone is tens of km thick and the core is thousands of degrees — ✓ the right answer · no support
3. You'd come out in China, not Australia — no support
4. Nothing, you would just need a long spade and a few weeks of hard digging — 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 3 · wrong ✗

"if u could drive a car straight down at 100 km/h, how long to the centre?"

1. About 6 hours, less than a day — ← Mova's choice · no support
2. About a year — no support
3. About 64 hours, almost three days — ✓ the right answer · no support
4. About 10 minutes — no support

Why: Nothing it remembers matched the question, so it guessed: it took the first option shown. · the question and its options parsed, with trees and pragmatics

Test 4 · wrong ✗

What would happen to compasses if the outer core stopped swirling?

1. The magnetic field would fade and compasses would stop working — ✓ the right answer · no support
2. Compasses would all point to the Sun instead of to the north — ← Mova's choice · score 6
3. Nothing, compasses work by gravity alone, not by magnetism — no support
4. Compasses would spin faster and faster — no support

Why: It took the question to ask what happens next. It chose option 2 with score 6, the only option with support. Its support: lesson 2, line 7: «A compass points to magnetic north, which is not the same place as the North Pole, and it has been drifting from the Canadian Arctic towards Siberia by tens of…», reached through the option's own match among the sentences about the question's things. What matched: the same action «point» (+2); the same doer «compass» (+2); the same circumstance (+2). The right option, 1, found no support in what it remembers. · the question and its options parsed, with trees and pragmatics

Test 5 · wrong ✗

Mia reckons the core must be the coldest place because it's furthest from the Sun. Right?

1. No, it's only as warm as a summer day — ← Mova's choice · no support
2. Yes, it's about the same temperature as the North Pole in winter — no support
3. No, it's about 5,000-6,000 °C from the Earth's own heat — ✓ the right answer · no support
4. Yes, it's frozen solid iron — 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 6 · right ✓

"bloody hell, they drilled 12 km and didn't even get through the crust??" Is that true?

1. No, they reached the mantle after 2 km — score 5
2. No, they went right through the mantle and touched the outer core — no support
3. No, the hole was only 12 metres deep — score 3
4. Yes, at Kola the continental crust is much thicker than 12 km — ← Mova's choice · ✓ the right answer · score 7

Why: It took the question to ask which statement is true. It chose option 4 with score 7, against 5 for the next best. Its support: lesson 41, line 7: «The crust is only about 5-10 km thick under the oceans and about 30-70 km thick under the continents.», reached through the remembered sentence the question matched. What matched: the same circumstance (+4); the same light verb (be, have, do, get, go) (+2); the same doer «crust» (+1). · the question and its options parsed, with trees and pragmatics

Test 7 · wrong ✗

In a video game, the core of the planet is a giant ball of ice. What is the real core like?

1. A frozen lake of water and ice — no support
2. Very hot rock that is liquid all through — no support
3. A ball of gas lighter than air — ← Mova's choice · score 8
4. Very hot iron and nickel, liquid outside and solid inside — ✓ the right answer · score 1

Why: It took the question to ask what it is done to. It chose option 3 with score 8, against 1 for the next best. Its support: lesson 41, line 10: «The inner core is a solid ball of iron and nickel about 2,400 km across (a radius of about 1,200 km), roughly as hot as the surface of the Sun, about 5,000-6,0…», reached through the remembered sentence the question matched. What matched: it fills the role the question asks for (+4); the same thing acted on «solid ball» (+2); the same doer «inner core» (+1); the same light verb (be, have, do, get, go) (+1). The right option, 4, scored 1. · the question and its options parsed, with trees and pragmatics

Test 8 · wrong ✗

Which is true about the inner core?

1. It is made of the same rock as the crust — ← Mova's choice · score 10
2. It is solid even though it is hotter than the liquid outer core — ✓ the right answer · score 5
3. It is hollow and full of air — no support
4. It is liquid because it is the hottest and deepest part of the Earth — score 5

Why: It took the question to ask which statement is true. It chose option 1 with score 10, against 5 for the next best. Its support: lesson 41, line 2: «The skin is the crust we live on, the flesh is the mantle of hot rock, and the stone is the core of iron and nickel, liquid outside and solid inside.», reached through the remembered sentence the question matched. What matched: the same thing acted on «crust» (+6); the same circumstance (+4). The right option, 2, scored 5. · the question and its options parsed, with trees and pragmatics

Test 9 · right ✓

A scientist sees earthquake waves bend and change speed deep down. What does that tell her?

1. The waves are crossing into a layer of different material — ← Mova's choice · ✓ the right answer · no support
2. The Earth is hollow there — no support
3. The waves are bouncing off the Moon — no support
4. The earthquake has stopped — 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 · wrong ✗

Your little brother asks: "Are the plates under the oceans made of just the crust?" What's the best answer?

1. No, plates are made of seawater ice — ← Mova's choice · no support
2. Yes, plates are only the thin crust under the sea floor — no support
3. No, plates are the crust plus the stiff top of the mantle — ✓ the right answer · no support
4. No, plates are pieces of the outer core — 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 11 · wrong ✗

Why is the Earth still hot inside after billions of years?

1. Volcanoes pump heat back down into it — no support
2. Radioactive elements keep making heat, and a planet that big cools very slowly — ✓ the right answer · score 2
3. The Sun heats it from the inside every day — no support
4. Burning oil underground keeps it warm — ← Mova's choice · score 4

Why: It took the question to ask why something happens (its cause). It chose option 4 with score 4, against 2 for the next best. Its support: lesson 23, line 12: «Gases such as carbon dioxide and methane trap some of the heat Earth gives off, keeping the planet warm enough for life; without them Earth would average about…», reached through the option's own match among the sentences about the question's things. What matched: the same action «keep» (+3); the same property (+1); a different thing acted on (counts against) (+1). Against it: a different doer (counts against) (-1). The right option, 2, scored 2. · 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 internal structure of the Earth?

1. A thin crust overlies a thick mantle, beneath which lie a liquid outer core and a solid inner core — ← Mova's choice · ✓ the right answer · no support
2. A thick crust overlies a liquid mantle, beneath which lie a solid outer core and a hollow inner region — no support
3. A molten mantle encloses an inner core composed principally of ice — no support
4. The planet consists of homogeneous solid rock from surface to centre — 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 2 · formal language · wrong ✗

Identify the principal means by which the composition of the Earth's interior has been ascertained.

1. Observation of the interior through volcanic craters — ← Mova's choice · no support
2. Photographic examination of the planet from orbit — no support
3. Direct sampling of the core by means of deep boreholes drilled for the purpose — no support
4. Analysis of the propagation of seismic waves through the planet — ✓ 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

Exam question 3 · formal language · right ✓

Select the response that is consistent with the established facts concerning the origin of the Earth's magnetic field.

1. It is generated by the motion of molten iron and nickel within the outer core — ← Mova's choice · ✓ the right answer · no support
2. It arises from magnetised rock in the oceanic crust alone — no support
3. It results from the gravitational attraction of the Moon — no support
4. It is induced in the planet by the light of the Sun — no support

Why: Nothing it remembers matched the question, so it guessed: it took the first option shown. · the question and its options parsed, with trees and pragmatics

Exam question 4 · formal language · wrong ✗

It is given that the Kola Superdeep Borehole attained a depth of approximately twelve kilometres. Ascertain which statement is correct in respect thereof.

1. The borehole penetrated through the mantle into the outer core — ← Mova's choice · no support
2. The borehole terminated within the continental crust — ✓ the right answer · no support
3. The borehole exceeded half the radius of the Earth — no support
4. The borehole reached the base of the mantle — 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

This page in Markdown → https://md.mova.elamur.ai/free/en/school-run/geography/41-inside-the-earth/