Rivers, lakes and the sea up close

Tests: 4 of 12 right · Exam: 2 of 4 right · Kind: plain · Understood: 12 of 16 · Run: 2026-10-18, commit f3c23ea72

Lesson 64 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 · wrong ✗

A town is built on the flat land right beside a big slow river. What danger should it plan for?

1. Sand dunes moving in from the river banks in the dry season — no support
2. The river running uphill — ← Mova's choice · score 6
3. Lava from the riverbed — no support
4. Floods when the river overflows onto its floodplain — ✓ the right answer · no support

Why: It took the question to ask what it is done to. It chose option 2 with score 6, the only option with support. Its support: lesson 49, line 14: «Rivers always flow from higher land to lower land, so a river flows away from the mountains.», reached through the remembered sentence the question matched. What matched: the same action «flow» (+4); the same doer «rivers» (+2). The right option, 4, found no support in what it remembers. · the question and its options parsed, with trees and pragmatics

Test 2 · wrong ✗

Rain falls on two sides of a long mountain ridge. On one side it ends up in one river, on the other side in a different river. What is the ridge called?

1. A watershed — ✓ the right answer · no support
2. A meander — no support
3. A floodplain — ← Mova's choice · score 7
4. A tributary — no support

Why: It took the question to ask what it is done to. It chose option 3 with score 7, the only option with support. Its support: lesson 64, line 2: «Near its source the river is fast and steep, cutting down into the land and carrying stones; in its middle and lower course it is slower and wider, swings from…», reached through the same lesson line as the sentence the question matched. What matched: it fills the role the question asks for (+4); the same thing acted on «floodplain» (+3). The right option, 1, found no support in what it remembers. · the question and its options parsed, with trees and pragmatics

Test 3 · wrong ✗

Which is true about the Earth's water?

1. Lakes hold more water than the oceans — score 3
2. Fresh and salt water are about equal — no support
3. Most of it is fresh water in rivers — ← Mova's choice · score 4
4. Nearly all of it is salty, and little of the fresh water is easy to reach — ✓ the right answer · no support

Why: It took the question to ask which statement is true. It chose option 3 with score 4, against 3 for the next best. Its support: lesson 14, line 15: «Most of Earth's water is salty water in the oceans; only a small part is fresh.», reached through the option's own match among the sentences about the question's things. What matched: the same doer «most» (+2); the same thing acted on «salty water» (+1); the same light verb (be, have, do, get, go) (+1). The right option, 4, found no support in what it remembers. · the question and its options parsed, with trees and pragmatics

Test 4 · right ✓

A fisherman notices that the sea comes high up the beach twice each day. What is mainly responsible?

1. The fish moving about the sea in large groups — no support
2. The rivers emptying their water into the sea — score 3
3. The wind changing direction twice every day — score 2
4. The Moon's gravity pulling on the ocean — ← Mova's choice · ✓ the right answer · score 10

Why: It took the question to ask which statement is true. It chose option 4 with score 10, against 3 for the next best. Its support: lesson 6, line 17: «The Moon's gravity pulls on the oceans and helps make the tides, the sea rising and falling along the shore about twice a day.», reached through the same lesson line as the sentence the question matched. What matched: the same action «pull» (+4); the same doer «gravity» (+4); the same circumstance (+2). · the question and its options parsed, with trees and pragmatics

Test 5 · wrong ✗

A river runs through steep mountains and later across a wide flat plain. Where will it most likely make big loops?

1. Right at its source — score 6
2. On the wide flat plain — ✓ the right answer · score 4
3. In the steep mountains — ← Mova's choice · score 9
4. Only where it is fastest — score 6

Why: It took the question to ask where. It chose option 3 with score 9, against 6 for the next best. Its support: lesson 49, line 14: «Rivers always flow from higher land to lower land, so a river flows away from the mountains.», reached through the remembered sentence the question matched. What matched: it fills the role the question asks for (+5); the same doer «river» (+3); the same place «mountains» (+3). Against it: a different action (counts against) (-2). The right option, 2, scored 4. · the question and its options parsed, with trees and pragmatics

Test 6 · right ✓

A city drains its marshes to build houses. What might happen next?

1. Floods become worse because nothing soaks up the water — ← Mova's choice · ✓ the right answer · score 1
2. The sea becomes fresh — no support
3. More birds come to live there — no support
4. The river stops flowing completely and dries up into a muddy ditch — no support

Why: It took the question to ask what happens next. It chose option 1 with score 1, the only option with support. Its support: lesson 63, line 11: «Sandy soil drains water quickly; clay soil holds water and drains slowly.», reached through what followed the sentence the question matched. What matched: the same thing acted on «water» (+4). Against it: a different doer (counts against) (-1); a different action (counts against) (-2). · the question and its options parsed, with trees and pragmatics

Test 7 · right ✓

Why does a big river keep growing as it flows towards the sea?

1. It melts the rocks of its bed — no support
2. Fish add water as they swim — no support
3. The sea pushes water into it — no support
4. Tributaries keep joining it — ← 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 64, line 6: «A tributary is a smaller river or stream that flows into a bigger river.», reached through the same lesson line as the sentence the question matched. What matched: the same doer «tributary» (+4); the same thing acted on «smaller river» (+2). · the question and its options parsed, with trees and pragmatics

Test 8 · wrong ✗

What would happen to waves on a lake if there were no wind at all for a long time?

1. The waves would grow bigger — ← Mova's choice · score 1
2. The water would turn salty — no support
3. The surface would become very calm — ✓ the right answer · no support
4. The lake would freeze — no support

Why: It took the question to ask what happens next. It chose option 1 with score 1, the only option with support. Its support: lesson 62, line 5: «An earthquake under the sea can lift the sea floor and push up a huge wave called a tsunami, which crosses the ocean as fast as a jet plane; if the sea suddenl…», reached through what followed the sentence the question matched. What matched: the same doer «huge wave» (+3). Against it: a different action (counts against) (-2). The right option, 3, found no support in what it remembers. · the question and its options parsed, with trees and pragmatics

Test 9 · wrong ✗

why can u float so easy in the dead sea

1. The water is so warm that it lifts you up — ← Mova's choice · no support
2. The water is so salty that it pushes you up much more — ✓ the right answer · no support
3. The sea is so shallow that you touch the bottom — no support
4. The waves there are strong enough to hold you up — 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 ✓

whats a tributary again

1. A smaller river or stream that flows into a bigger one — ← Mova's choice · ✓ the right answer · score 8
2. The flat land beside a river that floods — no support
3. A loop or bend in a slow lowland river — no support
4. The wide mouth where a river finally meets the open sea — no support

Why: It took the question to ask which statement is true. It chose option 1 with score 8, the only option with support. Its support: lesson 64, line 6: «A tributary is a smaller river or stream that flows into a bigger river.», reached through the same lesson line as the sentence the question matched. What matched: the same action «flow» (+4); the same doer «smaller river» (+4). · the question and its options parsed, with trees and pragmatics

Test 11 · wrong ✗

my cousin says most of the earth's water is fresh water we can drink. true?

1. No, most of it is frozen in the clouds — score 2
2. Yes, most water on Earth is in rivers and lakes — ← Mova's choice · score 4
3. Yes, rain makes most of the water on Earth fresh — score 3
4. No, about 97 parts in 100 are salty sea water — ✓ the right answer · score 4

Why: It took the question to ask which statement is true. It chose option 2 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 64, line 7: «A drainage basin is all the land whose water drains into one river.», reached through the option's own match among the sentences about the question's things. What matched: the same doer «water» (+2); the same place «one river» (+2). The right option, 4, scored 4. · the question and its options parsed, with trees and pragmatics

Test 12 · wrong ✗

teacher said tides come from the wind blowing the sea, i think he slipped?

1. Yes, tides come from the Earth's hot core heating the sea — no support
2. Yes, tides come mostly from the pull of the Moon's gravity — ✓ the right answer · no support
3. No, the wind is what makes the tides go in and out — no support
4. No, tides come from rivers pouring into the sea — ← Mova's choice · score 2

Why: It took the question to ask which statement is true. It chose option 4 with score 2, the only option with support. 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 option's own match among the sentences about the question's things. What matched: the same place «sea» (+2); the same circumstance (+2). Against it: a different action (counts against) (-1); a different doer (counts against) (-1). The right option, 2, found no support in what it remembers. · the question and its options parsed, with trees and pragmatics

Exam question 1 · formal language · right ✓

Which of the following statements most accurately characterises a tributary?

1. A smaller river or stream flowing into a larger river — ← Mova's choice · ✓ the right answer · no support
2. The flat land covered by a river in flood — no support
3. A loop or bend in the lower course of a river — no support
4. The point at which a river enters 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 2 · formal language · wrong ✗

Ascertain the proportion of the Earth's water which is salty sea water.

1. About 3 parts in 100 — ← Mova's choice · no support
2. About 50 parts in 100 — no support
3. About 75 parts in 100 — no support
4. About 97 parts in 100 — ✓ 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 ✓

Identify the principal cause of the tides upon the Earth's oceans.

1. The pull of the Moon's gravity upon the oceans — ← Mova's choice · ✓ the right answer · score 6
2. Earthquakes occurring beneath the sea — score 3
3. The wind blowing over the surface of the sea — no support
4. The flow of rivers into the oceans — no support

Why: It took the question to ask which statement is true. It chose option 1 with score 6, against 3 for the next best. Its support: lesson 6, line 17: «The Moon's gravity pulls on the oceans and helps make the tides, the sea rising and falling along the shore about twice a day.», reached through the same lesson line as the sentence the question matched. What matched: the same action «pull» (+4); the same circumstance (+2). · the question and its options parsed, with trees and pragmatics

Exam question 4 · formal language · wrong ✗

Select the response that is consistent with the established facts concerning the location of the greater part of the Earth's fresh water.

1. It flows in rivers and streams — ← Mova's choice · no support
2. It is suspended as clouds in the sky — no support
3. It is frozen in ice or lies underground — ✓ the right answer · no support
4. It is contained in lakes such as Baikal — 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

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