Mercury
Tests: 8 of 11 right · Exam: 1 of 4 right · Kind: plain · Understood: 7 of 15 · Run: 2026-10-18, commit f3c23ea72
Lesson 3 of the space 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 ✓
quiz q: closest planet to the Sun = hottest planet, yeah?
- 1. Yes, the closer the hotter, every time, that's the rule — no support
- 2. Yes, Mercury is always the hottest — no support
- 3. No, Earth is the hottest planet — no support
- 4. No, Venus is hotter because its thick air traps heat — ← 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 3, line 11: «Although Mercury is closest to the Sun, it is not the hottest planet; Venus is, because its thick air traps heat.», reached through the same lesson line as the sentence the question matched. What matched: the same action «trap» (+2); the same doer «thick air» (+2); the same thing acted on «heat» (+2). · the question and its options parsed, with trees and pragmatics
Test 2 · right ✓
Why does Mercury get so cold at night when it is so close to the Sun?
- 1. Its iron core sucks the heat away — no support
- 2. It has almost no air to hold the heat in — ← Mova's choice · ✓ the right answer · score 3
- 3. Its ice caps cool the whole planet — no support
- 4. Its night side faces away from the Sun forever — no support
Why: It took the question to ask why something happens (its cause). It chose option 2 with score 3, the only option with support. Its support: lesson 3, line 4: «Mercury has almost no air to hold heat, like a desert night but far worse: the day side is hot enough to melt lead and the night side colder than Antarctica.», reached through the option's own match among the sentences about the question's things. What matched: the same action «hold» (+2); the same thing acted on «heat» (+2). Against it: a different doer (counts against) (-1). · the question and its options parsed, with trees and pragmatics
Test 3 · wrong ✗
How can a day on Mercury last longer than its year?
- 1. It does not spin at all — ← Mova's choice · no support
- 2. Its year is counted backwards — no support
- 3. It spins so slowly that one sunrise to the next takes two of its years — ✓ the right answer · no support
- 4. Its days are measured in Earth weeks — 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 · right ✓
How can ice survive on the planet closest to the Sun?
- 1. It snows on Mercury every single night when it gets cold — no support
- 2. The Sun never shines on Mercury — no support
- 3. It sits in craters whose floors are always in shadow — ← Mova's choice · ✓ the right answer · score 8
- 4. The ice is kept under a layer of oil — no support
Why: It took the question to ask what something is like. It chose option 3 with score 8, the only option with support. Its support: lesson 3, line 5: «Even so, it is not the hottest planet, and in deep shady craters near its poles there is ice, like snow that lasts all spring in a corner the sun never reaches.», reached through the remembered sentence the question matched. What matched: the same doer «ice» (+4); the same place «deep shady craters» (+4). · the question and its options parsed, with trees and pragmatics
Test 5 · wrong ✗
Imagine a peach where the stone is most of the fruit. Which planet is this like?
- 1. Saturn, with its light gas and icy rings — ← Mova's choice · no support
- 2. Mercury, with its huge iron core — ✓ the right answer · no support
- 3. Venus, with its thick, hot yellow clouds — no support
- 4. Jupiter, with its bright colourful stripes — 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 · wrong ✗
A raisin is a shrunken grape with wrinkled skin. What on Mercury is like that?
- 1. Its craters, made by rocks crashing into it — ← Mova's choice · no support
- 2. Its ice, hidden away in deep, dark shadow — no support
- 3. Its scarps, made as the planet shrank — ✓ the right answer · no support
- 4. Its long tail, made by the solar wind blowing — 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 ✓
Why does Mercury keep its craters for billions of years?
- 1. Its moons protect them — no support
- 2. It has no air, rain or moving plates to wear them away — ← Mova's choice · ✓ the right answer · score 8
- 3. The Sun bakes them hard like pottery in a kiln, so they last — score 6
- 4. Its craters are refilled every year — score 3
Why: It took the question to ask why something happens (its cause). It chose option 2 with score 8, against 6 for the next best. Its support: lesson 3, line 16: «Mercury has no air, rain or moving plates of crust to wear its craters away, so they last for billions of years.», reached through a sentence linked to the one the question matched. What matched: the same action «move» (+2); the same doer «mercury» (+2); the same thing acted on «plates» (+2); its «because» matches the remembered cause (+2). · the question and its options parsed, with trees and pragmatics
Test 8 · right ✓
Why is it surprisingly hard to put a spacecraft into orbit around Mercury?
- 1. Mercury has no gravity at all — no support
- 2. The heat melts any craft at once — no support
- 3. Mercury is hidden behind the Sun forever — no support
- 4. It must brake hard against the Sun's pull, so it uses flybys of planets — ← 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 3, line 17: «A spacecraft falling towards the Sun speeds up, so to stay in orbit round Mercury it must brake hard; it slows itself by flying past planets on the way.», reached through a sentence linked to the one the question matched. What matched: the same action «break» (+2); the same doer «spacecraft» (+2); the same property (+1). · the question and its options parsed, with trees and pragmatics
Test 9 · right ✓
Tom says he saw Mercury high overhead at midnight. What is wrong?
- 1. Nothing, that is the best time — no support
- 2. Mercury only shows in winter — no support
- 3. Mercury never strays far from the Sun, so it is seen only low near dawn or dusk — ← Mova's choice · ✓ the right answer · score 8
- 4. Mercury can be seen only with a telescope — 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 1, line 4: «Light is fast but the Sun is far, so when you watch a sunset you see the Sun as it was about 8 minutes earlier.», reached through the remembered sentence the question matched. What matched: the same action «see» (+4); the same thing acted on «sun» (+4). · the question and its options parsed, with trees and pragmatics
Test 10 · right ✓
In a game, Mercury is the biggest of the rocky planets. What should it be?
- 1. The second biggest planet of them all — score 10
- 2. The smallest of all the planets — ← Mova's choice · ✓ the right answer · score 13
- 3. The same size as the Earth, or nearly — no support
- 4. Bigger than the giant planet Jupiter — score 10
Why: It took the question to ask what it is done to. It chose option 2 with score 13, against 10 for the next best. Its support: lesson 3, line 1: «Mercury is the smallest planet and the closest to the Sun, a grey, cratered ball only a little bigger than our Moon.», reached through the remembered sentence the question matched. What matched: it fills the role the question asks for (+6); the same thing acted on «smallest planet» (+4); the same property (+3); 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 11 · right ✓
Which is true: Mercury is heavier than Titan, or wider than Titan?
- 1. Heavier, but not wider — ← Mova's choice · ✓ the right answer · no support
- 2. Wider, but not heavier — no support
- 3. Neither heavier nor wider — no support
- 4. Both heavier and wider — 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 · wrong ✗
Identify the planet which completes its orbit of the Sun in the shortest period.
- 1. Mars, in some six hundred and eighty-seven days — ← Mova's choice · no support
- 2. The Earth, in some three hundred and sixty-five days — no support
- 3. Mercury, in some eighty-eight Earth days — ✓ the right answer · no support
- 4. Venus, in some two hundred and twenty-five days — 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 ✗
State the principal reason for which the night-side temperature of Mercury falls to approximately minus one hundred and eighty degrees Celsius.
- 1. Its great distance from the Sun — ← Mova's choice · no support
- 2. The presence of extensive polar oceans — no support
- 3. The near absence of an atmosphere capable of retaining heat — ✓ the right answer · no support
- 4. The shielding effect of its numerous moons — 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 ✓
Which of the following statements is consistent with the established facts concerning the interior of Mercury?
- 1. An iron core occupies the greater part of its interior — ← Mova's choice · ✓ the right answer · no support
- 2. It contains a global subsurface ocean of water — no support
- 3. It is entirely hollow, being composed of a thin rocky shell — no support
- 4. It consists principally of hydrogen and helium gas — 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 ✗
Ascertain the circumstances under which Mercury may be observed from the Earth.
- 1. At no time, it being invisible from the Earth — ← Mova's choice · no support
- 2. High in the southern sky at midnight — no support
- 3. Low in the sky shortly after sunset or before sunrise — ✓ the right answer · no support
- 4. Solely during a total lunar eclipse, when the sky is darkest — 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/space/3-mercury/