Animal builders: beavers, dams and lodges

Tests: 6 of 11 right · Exam: 3 of 4 right · Kind: plain · Understood: 11 of 15 · Run: 2026-10-18, commit f3c23ea72

Lesson 242 of the biology 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 ✓

In a cartoon a beaver builds a cosy house with a hammer, nails and a saw. How does a real beaver build?

1. With sticks glued together with honey — score 6
2. With hammers, saws and other tools it steals from people at night — score 5
3. With teeth, paws and mud, pushing sticks into the bottom and plastering them — ← Mova's choice · ✓ the right answer · score 12
4. It digs a hole and never builds anything — score 6

Why: It took the question to ask what something is like. It chose option 3 with score 12, against 6 for the next best. Its support: lesson 242, line 9: «Beavers have no hammer or nails: they push sticks into the mud bottom, pile them up and plaster them with mud carried against their chests.», reached through the same lesson line as the sentence the question matched. What matched: the same action «push» (+5); the same thing acted on «sticks» (+3); the same place «mud bottom» (+3); a different doer (counts against) (+1). · the question and its options parsed, with trees and pragmatics

Test 2 · wrong ✗

«there's a beaver dam on the news, my uncle reckons beavers plan it all like an architect» What is right?

1. No, people build the dams and beavers just live in them — ← Mova's choice · score 3
2. No, experiments show much of it is instinct set off by the sound of running water — ✓ the right answer · no support
3. Yes, the oldest beaver in the family tells the others where each stick must go, one at a time — no support
4. Yes, they draw plans in the mud first — no support

Why: It took the question to ask which statement is true. It chose option 1 with score 3, the only option with support. Its support: lesson 242, line 6: «Beavers build dams of sticks, stones and mud to make a deep pond, and the biggest known beaver dam, in Canada, is about 850 metres long and shows up in satelli…», reached through the option's own match among the sentences about the question's things. What matched: the same action «build» (+4); the same thing acted on «dams» (+1). Against it: a different doer (counts against) (-2). The right option, 2, found no support in what it remembers. · the question and its options parsed, with trees and pragmatics

Test 3 · right ✓

«5 beavers on the dam. how many legs then»

1. 20 — ← Mova's choice · ✓ the right answer · no support
2. 25 — no support
3. 10 — no support
4. 15 — 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 · wrong ✗

«3 beavers, no wait, 4 beavers slapping their tails. how many tails»

1. 8 — ← Mova's choice · no support
2. 12 — no support
3. 3 — no support
4. 4 — ✓ 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 5 · wrong ✗

What would happen if a farmer knocked a small hole in a beaver dam?

1. The beavers would leave and never come back to that pond again — no support
2. The pond would freeze straight away — no support
3. The beavers would hear the leak and soon fix it — ✓ the right answer · no support
4. Nothing, beavers never fix their dams — ← Mova's choice · score -1

Why: It took the question to ask what happens next. It chose option 4 with score -1, the only option with support. Its support: lesson 242, line 14: «Some dams have been repaired for hundreds of years by family after family of beavers, each one fixing the dam it inherited.», reached through the option's own match among the sentences about the question's things. Against it: a different action (counts against) (-1). The right option, 3, found no support in what it remembers. · the question and its options parsed, with trees and pragmatics

Test 6 · right ✓

«a beaver chewed through a tree and it fell on him. thick animal» What is true?

1. Beavers cannot control well which way a tree falls, so it does sometimes happen — ← Mova's choice · ✓ the right answer · score 12
2. Beavers always make trees fall exactly where they want, every single time without fail — score 8
3. It cannot happen because beavers cut only dead trees — score 9
4. Beavers jump on top of the tree as it falls — score 8

Why: It took the question to ask which statement is true. It chose option 1 with score 12, against 9 for the next best. Its support: lesson 242, line 15: «Beavers cannot control well which way a tree falls, and falling trees sometimes kill them; trees near water often lean towards the water anyway.», reached through the option's own match among the sentences about the question's things. What matched: the same action «control» (+4); the same doer «beavers» (+4); the same property (+3); the same thing acted on «way» (+1). · the question and its options parsed, with trees and pragmatics

Test 7 · wrong ✗

Your friend says beavers being brought back to British rivers will only cause floods. What is closer to the truth?

1. Beavers always flood the nearest towns and wash away the roads and farms — ← Mova's choice · no support
2. Beavers drink the rivers dry — no support
3. Beavers have no effect on rivers at all — no support
4. Their ponds slow floods, clean water and make homes for wildlife — ✓ 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 8 · right ✓

Why does a beaver pond keep a stream flowing in a dry summer?

1. Beavers dig wells for the stream — score -1
2. The pond makes rain fall — no support
3. The pond holds water and lets it out slowly — ← Mova's choice · ✓ the right answer · score 5
4. Beavers carry water from the sea — no support

Why: It took the question to ask why something happens (its cause). It chose option 3 with score 5, against -1 for the next best. Its support: lesson 242, line 17: «Beaver ponds slow floods, clean water and keep streams flowing in dry seasons; in America green strips were seen along beaver streams during droughts and wildf…», reached through the same lesson line as the sentence the question matched. What matched: the same action «keep» (+5); the same doer «beaver ponds» (+2). Against it: a different thing acted on (counts against) (-2). · the question and its options parsed, with trees and pragmatics

Test 9 · right ✓

«how do they even see underwater, mate, do they wear goggles lol»

1. They have see-through eyelids that work like goggles — ← Mova's choice · ✓ the right answer · score 9
2. They keep their heads above the water — no support
3. They shut their eyes tight and swim blind, feeling their way — no support
4. They see only with their whiskers — no support

Why: It took the question to ask which statement is true. It chose option 1 with score 9, the only option with support. Its support: lesson 242, line 13: «Beavers can stay underwater for about 15 minutes, and see-through eyelids work like swimming goggles.», reached through the option's own match among the sentences about the question's things. What matched: the same action «work» (+4); the same doer «see through eyelids» (+4); the same circumstance (+1). · the question and its options parsed, with trees and pragmatics

Test 10 · right ✓

A young beaver is two years old. What will it most likely do soon?

1. Leave home to find a mate and build its own pond — ← Mova's choice · ✓ the right answer · score 10
2. Move into a fox's den — no support
3. Become the leader of its parents' family — no support
4. Stay in the lodge with its parents for ever — no support

Why: It took the question to ask what is done. It chose option 1 with score 10, the only option with support. Its support: lesson 242, line 11: «A beaver family is the parents, this year's kits and last year's young, who help to build; young beavers leave at about two years old to make their own pond.», reached through the option's own match among the sentences about the question's things. What matched: it fills the role the question asks for (+4); the same action «make» (+3); the same thing acted on «own pond» (+3). · the question and its options parsed, with trees and pragmatics

Test 11 · wrong ✗

What does a beaver keep underwater near the lodge in autumn?

1. A pile of branches to eat in winter — ✓ the right answer · no support
2. Its old teeth — ← Mova's choice · score 4
3. Fish to eat in the spring, kept fresh in the cold — no support
4. A pile of stones that it uses for building — no support

Why: It took the question to ask what it is done to. It chose option 2 with score 4, the only option with support. Its support: lesson 242, line 10: «A lodge has a dry room above the water, an underwater door, a store of branches kept underwater near by for winter food, a breathing hole at the top, and walls…», reached through the remembered sentence the question matched. What matched: the same action «keep» (+5). Against it: a different thing acted on (counts against) (-1). The right option, 1, 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 the construction of a beaver dam?

1. It is constructed of sticks, stones and mud, without the employment of any tool — ← Mova's choice · ✓ the right answer · no support
2. It is excavated, rather than built, in the bed of the stream — no support
3. It is formed of ice deposited by the animals in winter — no support
4. It is erected with implements appropriated from human dwellings — 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 function of the pond impounded behind a beaver dam.

1. The irrigation of crops planted by the beavers — no support
2. The provision of deep water which does not freeze to the bed, wherein a protected lodge may be situated — ✓ the right answer · no support
3. The drowning of predators which approach the colony, chiefly wolves, bears and lynxes by night — no support
4. The cultivation of fish for consumption by the beavers during the winter months, when they cannot leave the water — ← Mova's choice · score 3

Why: It took the question to ask which statement is true. It chose option 4 with score 3, the only option with support. Its support: lesson 242, line 11: «A beaver family is the parents, this year's kits and last year's young, who help to build; young beavers leave at about two years old to make their own pond.», reached through a sentence linked to the one the question matched. What matched: the same action «leave» (+3); the same doer «young beavers» (+3). Against it: one says «not», the other does not (counts against) (-3). The right option, 2, found no support in what it remembers. · the question and its options parsed, with trees and pragmatics

Exam question 3 · formal language · right ✓

Select the response consistent with the established facts concerning experiments in which the sound of flowing water was reproduced through a loudspeaker.

1. The beavers abandoned the vicinity permanently — no support
2. The beavers dismantled the loudspeaker entirely and consumed its wooden and metal parts over a period of some days — no support
3. The beavers deposited sticks upon the loudspeaker, indicating that building is in large measure instinctive — ← Mova's choice · ✓ the right answer · score 3
4. The beavers exhibited no response of any description — no support

Why: It took the question to ask which statement is true. It chose option 3 with score 3, the only option with support. Its support: lesson 242, line 8: «In experiments, beavers piled sticks on a loudspeaker playing the sound of running water, so the sound of a leak makes them build: much of their building is in…», reached through the option's own match among the sentences about the question's things. What matched: the same doer «beavers» (+4); the same thing acted on «sticks» (+1). Against it: a different action (counts against) (-2). · the question and its options parsed, with trees and pragmatics

Exam question 4 · formal language · right ✓

Ascertain the reason for which the beaver is designated an ecosystem engineer.

1. It confines its activity exclusively to its own lodge — no support
2. It is employed by engineers in the construction of bridges across wide rivers — no support
3. Its works alter the landscape and furnish habitats for numerous other species — ← Mova's choice · ✓ the right answer · score 8
4. It removes all vegetation from the banks of rivers — no support

Why: It took the question to ask which statement is true. It chose option 3 with score 8, the only option with support. Its support: lesson 242, line 2: «When you see a tree in the park chewed into a pencil point, a beaver has been working there, cutting wood to build a dam across a stream.», reached through the option's own match among the sentences about the question's things. What matched: the same action «work» (+4); the same doer «beaver» (+4). · the question and its options parsed, with trees and pragmatics

This page in Markdown → https://md.mova.elamur.ai/free/en/school-run/biology/242-animal-builders-beavers-dams-and-lodges/