Rivers, canals and boats: locks, weirs, water-mills, barges and how not to tip a rowing boat
Tests: 6 of 11 right · Exam: 3 of 4 right · Kind: ★★ · Understood: 9 of 15 · Run: 2026-10-18, commit f3c23ea72
Lesson 41 of the technology 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 ✗
«canals are just rivers innit» What is right?
- 1. A canal is a river that has been frozen solid — ← Mova's choice · score 10
- 2. A canal is a river that only flows at night — score 10
- 3. Yes, canals and rivers are exactly the same thing with a different name — no support
- 4. A canal is dug by people, while a river is natural — ✓ the right answer · no support
Why: It took the question to ask which statement is true. It chose option 1 with score 10, tied with another option at 10 (the first shown, or the one claiming less beyond what it knows, wins). Its support: lesson 41, line 2: «A canal is a river made by people. About 250 years ago Britain dug thousands of kilometres of canals, because a single horse walking on the towpath could pull…», reached through the remembered sentence the question matched. What matched: the same doer «canal» (+4); the same thing acted on «river» (+4); the same light verb (be, have, do, get, go) (+2). The right option, 4, found no support in what it remembers. · the question and its options parsed, with trees and pragmatics
Test 2 · ★★ · right ✓
A Victorian boatman says one horse on the towpath does the work of fifteen horses with carts. How can that be?
- 1. It was a lie, as boats are much harder to pull than carts — score 4
- 2. A horse can pull about 30 tonnes by boat but about 2 tonnes by cart — ← Mova's choice · ✓ the right answer · score 14
- 3. The boat had fifteen more horses hidden inside it — no support
- 4. Canal horses ate fifteen times as much food as other horses — no support
Why: It took the question to ask what something is like. It chose option 2 with score 14, against 4 for the next best. Its support: lesson 41, line 7: «A horse that could pull about 2 tonnes in a cart on a road could pull a canal boat carrying about 30 tonnes, because water holds the boat up and there are no b…», reached through the remembered sentence the question matched. What matched: the same action «pull about» (+4); the same thing acted on «2 tonnes» (+4); the same doer «horse» (+3); the same circumstance (+3). · the question and its options parsed, with trees and pragmatics
Test 3 · ★★ · wrong ✗
In the book Toad offers to steer the barge instead of washing. What steers a barge?
- 1. The horse's reins — ← Mova's choice · no support
- 2. A steering wheel on the roof — no support
- 3. The tiller at the back — ✓ the right answer · no support
- 4. The oars at the front — 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 ✓
«how does a lock lift a whole boat with no engine» What is the best answer?
- 1. Water flows in from the higher canal and the boat floats up with it — ← Mova's choice · ✓ the right answer · no support
- 2. A man winds the boat up with a big handle and a heavy chain — no support
- 3. Magnets under the water push the boat up slowly — no support
- 4. The boat's own engine climbs straight up the walls — 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 · ★★ · right ✓
Portly goes missing and the Otter fears the weir. Why is a weir dangerous for a small swimmer?
- 1. Weirs are electric — no support
- 2. Weirs suck everything up into the air — no support
- 3. The churning water below it can hold a swimmer under — ← Mova's choice · ✓ the right answer · score 7
- 4. The water above a weir is always boiling hot in summer — score 3
Why: It took the question to ask why something happens (its cause). It chose option 3 with score 7, against 3 for the next best. Its support: lesson 41, line 13: «A weir is a low wall across a river that keeps the water deep upstream for boats and can send water to a mill; below it the water churns round and round and ca…», reached through the option's own match among the sentences about the question's things. What matched: the same thing acted on «swimmer» (+3); the same action «hold under» (+2); the same doer «water» (+2). · the question and its options parsed, with trees and pragmatics
Test 6 · ★★ · wrong ✗
«we're going on a narrowboat holiday, can we go 30 mph to get there quicker?» What is right?
- 1. Yes, but only at night when the canal is empty of boats — ← Mova's choice · no support
- 2. Yes, narrowboats are built to go as fast as cars on the motorway — no support
- 3. No, the limit is 3 miles a day, to save fuel — no support
- 4. No, the canal speed limit is 4 miles an hour, to protect the banks — ✓ 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 7 · ★★ · right ✓
The Mole grabs the sculls, lunges and «Sploosh! Over went the boat». What should you do in a small boat?
- 1. Lean right out over one side — no support
- 2. Stand up and wave the oars to keep your balance — score 7
- 3. Jump from side to side to test it — score 2
- 4. Step into the middle, keep low and sit still — ← Mova's choice · ✓ the right answer · score 8
Why: It took the question to ask what is done. It chose option 4 with score 8, against 7 for the next best. Its support: lesson 41, line 17: «Small boats tip over easily if someone stands up or lunges to one side, as the Mole did when he grabbed the sculls; you step into the middle, keep low, sit sti…», 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 action «keep» (+3); the same property (+1). · the question and its options parsed, with trees and pragmatics
Test 8 · ★★ · right ✓
A painting shows a narrowboat cabin covered in roses and castles. Who lived there?
- 1. The lock-keeper's cat — no support
- 2. Often a whole boat family — ← Mova's choice · ✓ the right answer · score 9
- 3. The horse — no support
- 4. Nobody, it was only for coal — no support
Why: It took the question to ask who or what does it. It chose option 2 with score 9, the only option with support. Its support: lesson 41, line 9: «Narrowboats are only about 2 metres wide, to fit the narrow locks, and up to about 21 metres long; many boat families lived in a tiny cabin at the back, painte…», reached through the remembered sentence the question matched. What matched: it fills the role the question asks for (+4); the same action «live» (+3); the same doer «many boat families» (+2). · the question and its options parsed, with trees and pragmatics
Test 9 · ★★ · right ✓
«the rat rows facing backwards?? thats dumb» Why do rowers and scullers face backwards?
- 1. They pull the oars towards themselves, which is the strongest way to row — ← Mova's choice · ✓ the right answer · score 8
- 2. They are too scared to see where they are going — no support
- 3. They want to see the people behind them on the bank — no support
- 4. It is just a silly rule invented for races in Oxford — no support
Why: It took the question to ask why something happens (its cause). It chose option 1 with score 8, the only option with support. Its support: lesson 41, line 15: «Sculling means one person rows with two oars called sculls, as the Rat does; in rowing each person holds one oar with both hands; both face backwards, because…», reached through the cause of the sentence the question matched. What matched: the same thing acted on «strongest way» (+4); its «because» matches the remembered cause (+4); the same light verb (be, have, do, get, go) (+2). Against it: a different doer (counts against) (-2). · the question and its options parsed, with trees and pragmatics
Test 10 · ★★ · wrong ✗
A friend says the old mill wheel turned because a horse walked round and round it. What really turned a water-mill?
- 1. A steam engine under it — ← Mova's choice · score 9
- 2. A horse walking round it — score 9
- 3. Moving water pushing the wheel — ✓ the right answer · no support
- 4. Wind in its four sails — no support
Why: It took the question to ask who or what does it. It chose option 1 with score 9, tied with another option at 9 (the first shown, or the one claiming less beyond what it knows, wins). Its support: lesson 17, line 2: «Gears are like the gears on a bike: low gears give a strong push to start and climb hills, high gears let the wheels turn fast while the engine turns slowly.», reached through the same lesson line as the sentence the question matched. What matched: the same action «turn» (+4); it fills the role the question asks for (+3); the same doer «engine» (+2). The right option, 3, found no support in what it remembers. · the question and its options parsed, with trees and pragmatics
Test 11 · ★★ · wrong ✗
★★★ A lock is 20 metres long and 2 metres wide, and the water rises 3 metres to lift a boat. How many cubic metres of water flow in?
- 1. 25 — ← Mova's choice · no support
- 2. 120 — ✓ the right answer · no support
- 3. 60 — no support
- 4. 1200 — 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 ✓
Identify the principal advantage of conveying heavy goods by canal rather than by road in the eighteenth century.
- 1. A single horse could draw a far greater load upon the water — ← Mova's choice · ✓ the right answer · no support
- 2. Canals were open to traffic only at night, when the roads were closed — no support
- 3. Road carts were forbidden by law — no support
- 4. Boats required no persons whatsoever to steer them — 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 · right ✓
Select the response consistent with the established facts concerning the operation of a canal lock.
- 1. The vessel is hauled up a ramp by a team of horses — no support
- 2. The water is boiled until it rises — no support
- 3. The vessel is raised by an engine of great power concealed beneath the lock — no support
- 4. Water admitted from the higher level raises the vessel, no pump being required — ← Mova's choice · ✓ the right answer · 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 41, line 11: «A lock needs no pump: water simply flows down from the higher part of the canal, and reservoirs keep the top of the canal full.», reached through the option's own match among the sentences about the question's things. What matched: the same action «need» (+1); the same thing acted on «pump» (+1). · the question and its options parsed, with trees and pragmatics
Exam question 3 · formal language · right ✓
Ascertain the reason for which bathing in the vicinity of a weir is to be avoided.
- 1. The circulating water below the weir may hold a swimmer beneath the surface — ← Mova's choice · ✓ the right answer · no support
- 2. The water above the weir is invariably polluted by the mill — no support
- 3. Bathing is permitted only on Sundays — no support
- 4. Weirs are inhabited by dangerous eels which bite any bather they encounter — 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 · wrong ✗
Which of the following statements most accurately characterises the practice of sculling?
- 1. Two persons propel the boat with a single oar between them — ← Mova's choice · score 5
- 2. A single person propels the boat with a pair of oars — ✓ the right answer · score 4
- 3. The boat is drawn by a horse upon the bank — no support
- 4. The boat is propelled by a pole upon the river bed — no support
Why: It took the question to ask who or what does it. It chose option 1 with score 5, against 4 for the next best. Its support: lesson 41, line 15: «Sculling means one person rows with two oars called sculls, as the Rat does; in rowing each person holds one oar with both hands; both face backwards, because…», reached through the same lesson line as the sentence the question matched. What matched: it fills the role the question asks for (+3); the same doer «one person» (+2); the same circumstance (+1). Against it: a different action (counts against) (-1). The right option, 2, scored 4. · the question and its options parsed, with trees and pragmatics
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