Mountains, rivers and seas, and how the land is shaped

Tests: 8 of 13 right · Exam: 1 of 4 right · Kind: ★ · Understood: 11 of 17 · Run: 2026-10-18, commit f3c23ea72

Lesson 43 of the world 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 ✓

Climbers find shells of sea animals in rocks near the top of a high mountain. How can that be?

1. Climbers dropped the shells there long ago — no support
2. The rock formed under the sea and was pushed up as plates collided — ← Mova's choice · ✓ the right answer · score 8
3. The sea once reached as high as the mountain top — no support
4. Birds carried the shells up the mountain one by one — no support

Why: It took the question to ask what something is like. It chose option 2 with score 8, the only option with support. Its support: lesson 43, line 20: «Some rock high in mountains formed long ago under the sea and was pushed up when plates collided, so it can hold shells of sea animals.», reached through the same lesson line as the sentence the question matched. What matched: the same action «form» (+3); the same doer «rock» (+3); the same place «sea» (+2). · the question and its options parsed, with trees and pragmatics

Test 2 · ★ · wrong ✗

Which change in the land happens fastest?

1. Rain wearing away a hill — ← Mova's choice · no support
2. An earthquake shaking the ground — ✓ the right answer · no support
3. A river cutting a deep valley — no support
4. Plates pushing up a mountain range — 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 ✗

A river is very muddy where it enters the sea, and the land there is flat and grows bigger every year. What is forming?

1. A glacier — ← Mova's choice · no support
2. A delta — ✓ the right answer · no support
3. A volcano — no support
4. A mountain range — 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 4 · ★ · right ✓

Which is true about lava and magma?

1. Lava is water and magma is melted ice — no support
2. Magma comes down from the Sun and lava comes from the Earth — no support
3. They are the same melted rock, above and below the ground — ← Mova's choice · ✓ the right answer · score 4
4. Lava is cold rock and magma is hot rock — score 4

Why: It took the question to ask which statement is true. It chose option 3 with score 4, tied with another option at 4 (the first shown, or the one claiming less beyond what it knows, wins). Its support: lesson 12, line 13: «Lava from a volcano is rock so hot that it has melted into a liquid; when it cools it freezes back into solid rock.», reached through the remembered sentence the question matched. What matched: the same doer «lava» (+2); the same thing acted on «rock» (+2). · the question and its options parsed, with trees and pragmatics

Test 5 · ★ · right ✓

Why are earthquakes and volcanoes common in the same places?

1. Both are caused by very strong winds blowing — no support
2. Both happen only near big rivers and lakes — no support
3. Both happen only in very cold countries — no support
4. Both happen mostly where plates meet — ← Mova's choice · ✓ the right answer · score 5

Why: It took the question to ask why something happens (its cause). It chose option 4 with score 5, the only option with support. Its support: lesson 43, line 19: «Most earthquakes and volcanoes happen where plates meet.», reached through the same lesson line as the sentence the question matched. What matched: the same doer «plates» (+3); the same action «meet» (+2). · the question and its options parsed, with trees and pragmatics

Test 6 · ★ · wrong ✗

A deep valley has steep sides like the letter V and a stream at the bottom. What made it?

1. A volcano that blew the rock away — ← Mova's choice · no support
2. The stream, wearing the rock away over thousands of years — ✓ the right answer · no support
3. An earthquake that split the ground wide open in a single day — no support
4. People who dug it to make a road — 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 7 · ★ · wrong ✗

A rock left in a sunny, frosty place cracks into pieces after many winters. What has happened?

1. An earthquake under the rock — no support
2. Weathering by freezing water in its cracks — ✓ the right answer · no support
3. Lava pouring over the rock — ← Mova's choice · score 2
4. The rock dried out and turned into sand at once — no support

Why: It took the question to ask which statement is true. It chose option 3 with score 2, the only option with support. Its support: lesson 12, line 13: «Lava from a volcano is rock so hot that it has melted into a liquid; when it cools it freezes back into solid rock.», reached through the option's own match among the sentences about the question's things. What matched: the same place «solid rock» (+2); the same doer «lava» (+1). Against it: a different action (counts against) (-1). The right option, 2, found no support in what it remembers. · the question and its options parsed, with trees and pragmatics

Test 8 · ★ · right ✓

Why is Mount Everest still very slowly getting higher?

1. India is still pushing into Asia and lifting the rock — ← Mova's choice · ✓ the right answer · no support
2. The volcano inside it keeps erupting — no support
3. Climbers bring stones to the top every year — no support
4. Snow keeps falling and piling up higher and higher on top of it — 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 9 · ★ · right ✓

Where does a river finish its journey?

1. Where the first bridge crosses it — no support
2. At its source, high in the mountains — score 9
3. At the deepest point of its valley — score 3
4. At its mouth — ← Mova's choice · ✓ the right answer · score 17

Why: It took the question to ask where. It chose option 4 with score 17, against 9 for the next best. Its support: lesson 43, line 12: «A river starts at its source and ends at its mouth, where it flows into a sea, a lake or another river.», reached through the remembered sentence the question matched. What matched: the same action «end» (+6); it fills the role the question asks for (+5); the same doer «river» (+3); the same place «mouth» (+3). · the question and its options parsed, with trees and pragmatics

Test 10 · ★ · right ✓

how'd a river make a whole valley, it's just water

1. Over thousands of years the sand and stones it carries cut the land — ← Mova's choice · ✓ the right answer · score 4
2. It floods once and digs it out — no support
3. The valley was there and the river found it — no support
4. Fish dig the valley as they swim — no support

Why: It took the question to ask which statement is true. It chose option 1 with score 4, the only option with support. Its support: lesson 43, line 13: «Over thousands of years a river cuts a valley into the land with the sand and stones it carries.», reached through the remembered sentence the question matched. What matched: the same place «thousands» (+4); the same circumstance (+4). Against it: a different action (counts against) (-2); a different doer (counts against) (-2). · the question and its options parsed, with trees and pragmatics

Test 11 · ★ · wrong ✗

lava n magma whats the diff

1. They are two different kinds of mountain — no support
2. Magma is ash and lava is gas — no support
3. Lava is hotter rock than magma — ← Mova's choice · score 4
4. Magma is melted rock underground, lava is the same rock on the surface — ✓ the right answer · score 4

Why: It took the question to ask which statement is true. It chose option 3 with score 4, tied with another option at 4 (the first shown, or the one claiming less beyond what it knows, wins). Its support: lesson 12, line 13: «Lava from a volcano is rock so hot that it has melted into a liquid; when it cools it freezes back into solid rock.», reached through the remembered sentence the question matched. What matched: the same doer «lava» (+2); the same thing acted on «rock» (+2). The right option, 4, scored 4. · the question and its options parsed, with trees and pragmatics

Test 12 · ★ · right ✓

my brother says mountains just popped up quickly ages ago. true?

1. No, they are slowly sinking into the sea — no support
2. Yes, volcanoes made all of them — no support
3. Yes, they popped up in one day — no support
4. No, they rise slowly as plates push together for millions of years — ← Mova's choice · ✓ the right answer · score 6

Why: It took the question to ask which statement is true. It chose option 4 with score 6, the only option with support. Its support: lesson 43, line 7: «Mountains rise where plates push against each other for millions of years.», reached through the remembered sentence the question matched. What matched: the same action «rise» (+4); the same doer «mountains» (+2). · the question and its options parsed, with trees and pragmatics

Test 13 · ★ · right ✓

Ava says most lakes are salty like the sea. right?

1. No, most lakes have fresh water — ← Mova's choice · ✓ the right answer · score 4
2. Yes, lakes are pieces of the sea — no support
3. Yes, all lakes are salty — no support
4. No, lakes have no water in winter — score 4

Why: It took the question to ask which statement is true. It chose option 1 with score 4, tied with another option at 4 (the first shown, or the one claiming less beyond what it knows, wins). Its support: lesson 43, line 5: «A lake is water resting in a hollow of the land, a sea is a part of the ocean partly closed by land, and a river is water flowing downhill in a channel from it…», reached through the remembered sentence the question matched. What matched: the same doer «lake» (+2); the same thing acted on «water» (+2). · the question and its options parsed, with trees and pragmatics

Exam question 1 · formal language · wrong ✗

Identify the principal cause of the formation of mountains.

1. The accumulation of snow upon the summits over many centuries — ← Mova's choice · no support
2. The deposit of sand by rivers — no support
3. The erosion of valleys by wind — no support
4. The pressure of the Earth's plates against one another — ✓ 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 2 · formal language · wrong ✗

Which of the following statements most accurately distinguishes magma from lava?

1. Magma lies beneath the ground; lava has emerged upon the surface — ✓ the right answer · score 5
2. Magma is solid rock; lava is liquid rock — ← Mova's choice · score 10
3. Magma has emerged upon the surface; lava lies beneath the ground — score 6
4. Magma is volcanic ash; lava is volcanic gas — score 6

Why: It took the question to ask who or what does it. It chose option 2 with score 10, against 6 for the next best. Its support: lesson 12, line 13: «Lava from a volcano is rock so hot that it has melted into a liquid; when it cools it freezes back into solid rock.», reached through the option's own match among the sentences about the question's things. What matched: the same thing acted on «rock» (+3); it fills the role the question asks for (+3); the same doer «lava» (+2); the same light verb (be, have, do, get, go) (+2). The right option, 1, scored 5. · the question and its options parsed, with trees and pragmatics

Exam question 3 · formal language · right ✓

Which of the following is designated by the term delta?

1. A deep valley carved by a glacier — no support
2. A lake lying in a hollow of the land — no support
3. Flat land formed from mud and sand deposited at a river's mouth — ← Mova's choice · ✓ the right answer · score 5
4. The source of a river among mountains — no support

Why: It took the question to ask who or what does it. It chose option 3 with score 5, the only option with support. Its support: lesson 43, line 4: «Water shapes the land too: a river carries sand and stones that scrape its bed, and over thousands of years it cuts a deep valley shaped like the letter V; whe…», reached through the same lesson line as the sentence the question matched. What matched: the same action «shape» (+3); the same thing acted on «land» (+2). · the question and its options parsed, with trees and pragmatics

Exam question 4 · formal language · wrong ✗

Identify the highest mountain upon the Earth.

1. Mont Blanc — ← Mova's choice · no support
2. Mount Denali — no support
3. Mount Everest — ✓ the right answer · no support
4. Mount Kilimanjaro — 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/world/43-landforms/