You are an experienced teacher who knows how to write good multiple-choice tests. From the course at the end of this message, write a test in the MCQ Advanced format (a .qcm.md file), ready for the teacher to review.

SETTINGS (the teacher may change them):
- Number of questions: 12
- Audience: high school students
- Language of the test: English

CONTENT
- Use only what the course says. If it is not enough for the number of questions asked, write fewer rather than make things up.
- Group the questions into 2 to 4 themes of the course, each with at least 3 questions.
- Aim at understanding and applying: at least half the questions at level 3 or above, at most one question in eight at level 1.
  Levels: 1 remember, 2 understand, 3 apply, 4 analyse, 5 evaluate.
- 3 or 4 answers per question, a single correct one most of the time.
- Wrong answers are mistakes students really make on this notion, not absurdities.
- The correct answer is no longer and no more precise than the others: students quickly spot the most careful answer. Its position (1st, 2nd, 3rd, 4th) varies from one question to the next.
- Never "all of the above" or "none of the above".
- A question asking for an exception puts the word in bold: "Which one is **not** ...?".
- Every statement asks a real question, ending with "?" or ":".
- Every answer, right or wrong, has a one or two sentence explanation saying why.
- Every question has a RULE: (the rule to remember, in one sentence) and a REVIEW: (the part of the course to revise). Every theme has a COURSE:.

FORMAT
- The file starts with a header between two "---" lines: title, description, lang (en, fr...), duration (in minutes), penalty: 0, scoring: all-or-nothing.
- duration: add up the times of all questions, add 20 %, round up to the minute.
- "# THEME id | Title" opens a theme, with "COURSE:" right under it.
- "## Q id | level N | Ns" opens a question: N from 1 to 5, Ns the answering time in seconds (10 to 60).
- Ids are lowercase, with hyphens, without accents, and all different.
- The statement follows, in Markdown. Code goes in a block with its language (```python). Formulas in LaTeX: $x^2$ inside a sentence, $$\frac{a}{b}$$ alone on its line. A real dollar sign is written \$.
- "- [x]" for a correct answer, "- [ ]" for a wrong one. Several [x] for a question with several answers.
- An answer's explanation is on the next line, starting with ">" and indented by two spaces.
- No image or sound: you cannot provide them.

=== EXAMPLE ===
---
title: The water cycle
description: End of chapter check
lang: en
duration: 2
penalty: 0
scoring: all-or-nothing
---

# THEME states | Changes of state
COURSE: Chapter 1, the states of water

## Q puddle-evaporation | level 3 | 30s
After the rain, a puddle disappears on a sunny day without ever boiling. What happened?

- [ ] The water all soaked into the ground
  > A puddle on a waterproof surface disappears too: soaking in does not explain everything.
- [x] The water evaporated at its surface
  > Evaporation happens at any temperature, well below 100 °C.
- [ ] The water boiled in the sunshine
  > Boiling takes 100 °C at sea level; the sun does not bring a puddle there.

RULE: Evaporation happens at any temperature, boiling at one precise temperature.
REVIEW: Chapter 1, evaporation and boiling

## Q cloud-condensation | level 2 | 20s
What is a cloud made of?

- [x] Tiny droplets of water
  > The vapour condensed into droplets (or ice crystals) too small to fall.
- [ ] Invisible water vapour
  > Vapour is an invisible gas: if you can see the cloud, it has condensed.
- [ ] Smoke from factories
  > Smoke can seed the droplets, but the cloud is still water.

RULE: A visible cloud is condensed water, not vapour.
REVIEW: Chapter 1, condensation

## Q floating-ice | level 4 | 40s
An ice cube floats in a glass of water filled to the brim. When it melts, what does the water level do?

- [ ] It rises and the glass overflows
  > The part above the surface seems to add water, but it only makes up for the lower density of ice.
- [ ] It drops a little
  > Ice loses no water when it melts: the mass stays the same.
- [x] It stays the same
  > The cube already displaces exactly its own mass of water; melted, it fills that same volume.

RULE: A floating body displaces its own mass of liquid.
REVIEW: Chapter 1, the density of ice
=== END OF EXAMPLE ===

REVIEW BEFORE ANSWERING
- Count the questions where the correct answer is the longest: no more than one in three. For the others, shorten the correct answer (the justification goes in its explanation) or lengthen a wrong one.
- No correct answer reaches one and a half times the length of the longest wrong answer.
- The positions of the correct answers are spread out, with no more than half of them at the same rank.

ANSWER
Reply with the content of the file only, from the first "---" line to the last explanation: no sentence before or after, no code block around it. The teacher pastes it as is into MCQ Advanced, which reviews it with its validator.

COURSE:
[paste your course here]