---
title: Identify the principal cause of the periodic collapse in the numbers… — Myth check: do lemmings jump off cliffs? · tree and pragmatics
description: Identify the principal cause of the periodic collapse in the numbers of lemmings. Exam question 2 of lesson 150 «Myth check: do lemmings jump off cliffs?» of the biology course of Mova's primary school, with the dependency tree and pragmatics of the question and of each option; Mova's choice was wro
---

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# Exam question 2 · Myth check: do lemmings jump off cliffs?

<!-- .ven lang=en -->
Identify the principal cause of the periodic collapse in the numbers of lemmings.

<!-- .vintro -->
**Mova's choice:** option 1 · **The right answer:** option 3 · wrong ✗ · **Who acts:** you · **What happens:** identify, cause · **To what, where:** principal cause, periodic collapse

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This is exam question 2 of lesson 150 «Myth check: do lemmings jump off cliffs?» of the biology course of Mova's primary school, asked in stiff, formal language. The page gives the question's syntax tree — a dependency tree in the style of Universal Dependencies — and its pragmatics clause by clause, then the 4 options as the student saw them, each with its tree and pragmatics. Every text is parsed by Mova itself. How the student answered it, with the score of every option and why: [the test at school](https://md.mova.elamur.ai/free/en/school-run/biology/150-myth-check-do-lemmings-jump-off-cliffs/#e2).

## The question {#question}

```conllu
# sent_id = question:biology:150-myth-check-do-lemmings-jump-off-cliffs:e2:1
# text = Identify the principal cause of the periodic collapse in the numbers of lemmings.
1	Identify	identify	VERB	VB	Mood=Imp|VerbForm=Fin	0	root	_	_
2	the	the	DET	DT	Definite=Def|PronType=Art	4	det	_	_
3	principal	principal	ADJ	JJ	Degree=Pos	4	amod	_	_
4	cause	cause	NOUN	NN	Number=Sing	1	obj	_	_
5	of	of	ADP	IN	_	8	case	_	_
6	the	the	DET	DT	Definite=Def|PronType=Art	8	det	_	_
7	periodic	periodic	ADJ	JJ	Degree=Pos	8	amod	_	_
8	collapse	collapse	NOUN	NN	Number=Sing	4	nmod	_	_
9	in	in	ADP	IN	_	11	case	_	_
10	the	the	DET	DT	Definite=Def|PronType=Art	11	det	_	_
11	numbers	number	NOUN	NNS	Number=Plur	8	nmod	_	_
12	of	of	ADP	IN	_	13	case	_	_
13	lemmings	lemming	NOUN	NNS	Number=Plur	11	nmod	_	SpaceAfter=No
14	.	.	PUNCT	.	_	1	punct	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **identify** | imperative | you *not said here* | the principal cause of the periodic collapse in the numbers of lemmings |  |  |  |  | vn characterize-29.2-1-1 «NP V NP S\_ING»: agent=Agent cause=Theme |
| 2 | **cause** |  |  | the periodic collapse in the numbers of lemmings |  |  |  |  | nom cause «event transitive»: of=patient |

<!-- .note -->
One row per clause the reader finds. «not said here»: a role filled from the clause above. «roles by»: a VerbNet class and frame when one fits the verb, else the reader's rules on the tree.

## The options {#options}

### Option 1 · ← Mova's choice {#o1}

<!-- .ven lang=en -->
A voluntary cessation of breeding

```conllu
# sent_id = question:biology:150-myth-check-do-lemmings-jump-off-cliffs:e2:o1:1
# text = A voluntary cessation of breeding
1	A	a	DET	DT	Definite=Ind|PronType=Art	3	det	_	_
2	voluntary	voluntary	ADJ	JJ	Degree=Pos	3	amod	_	_
3	cessation	cessation	NOUN	NN	Number=Sing	0	root	_	_
4	of	of	ADP	IN	_	5	case	_	_
5	breeding	breeding	NOUN	NN	Number=Sing	3	nmod	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **cease** |  |  | breeding |  |  |  |  | nom cessation «event transitive»: of=patient |

### Option 2 {#o2}

<!-- .ven lang=en -->
A deliberate mass descent into the sea

```conllu
# sent_id = question:biology:150-myth-check-do-lemmings-jump-off-cliffs:e2:o2:1
# text = A deliberate mass descent into the sea
1	A	a	DET	DT	Definite=Ind|PronType=Art	4	det	_	_
2	deliberate	deliberate	ADJ	JJ	Degree=Pos	4	amod	_	_
3	mass	mass	ADJ	JJ	Degree=Pos	4	amod	_	_
4	descent	descent	NOUN	NN	Number=Sing	0	root	_	_
5	into	into	ADP	IN	_	7	case	_	_
6	the	the	DET	DT	Definite=Def|PronType=Art	7	det	_	_
7	sea	sea	NOUN	NN	Number=Sing	4	nmod	_	_
```

<!-- .note -->
The frames reader finds no event or fact in this sentence.

### Option 3 · ✓ the right answer {#o3}

<!-- .ven lang=en -->
The exhaustion of the food supply together with an increase in predators

```conllu
# sent_id = question:biology:150-myth-check-do-lemmings-jump-off-cliffs:e2:o3:1
# text = The exhaustion of the food supply together with an increase in predators
1	The	the	DET	DT	Definite=Def|PronType=Art	2	det	_	_
2	exhaustion	exhaustion	NOUN	NN	Number=Sing	0	root	_	_
3	of	of	ADP	IN	_	6	case	_	_
4	the	the	DET	DT	Definite=Def|PronType=Art	6	det	_	_
5	food	food	NOUN	NN	Number=Sing	6	compound	_	_
6	supply	supply	NOUN	NN	Number=Sing	2	nmod	_	_
7	together	together	ADV	RB	_	6	advmod	_	_
8	with	with	ADP	IN	_	10	case	_	_
9	an	a	DET	DT	Definite=Ind|PronType=Art	10	det	_	_
10	increase	increase	NOUN	NN	Number=Sing	2	nmod	_	_
11	in	in	ADP	IN	_	12	case	_	_
12	predators	predator	NOUN	NNS	Number=Plur	10	nmod	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **exhaust** |  |  | the food supply |  |  |  | with a increase in predators | nom exhaustion «state transitive»: of=patient with=obl |

### Option 4 {#o4}

<!-- .ven lang=en -->
Migration southward to temperate regions

```conllu
# sent_id = question:biology:150-myth-check-do-lemmings-jump-off-cliffs:e2:o4:1
# text = Migration southward to temperate regions
1	Migration	migration	NOUN	NN	Number=Sing	4	nsubj	_	_
2	southward	southward	ADV	RB	_	4	advmod	_	_
3	to	to	PART	TO	_	4	mark	_	_
4	temperate	temperate	VERB	VB	VerbForm=Inf	0	root	_	_
5	regions	region	NOUN	NNS	Number=Plur	4	obj	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **temperate** | to-infinitive | Migration | regions |  |  |  | southward *property* | tree rules |

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**Text:** the tests of Mova's primary school, written for Mova (`world/data/school/`), as the course runner gave them to the student. **Trees:** Mova's own parse — the `en` model on the CPU, when the site is built — not checked by a teacher; they may be wrong. **Frames:** Mova's frames reader (`prag`), each text read on its own. Elamur Cosmic License.

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- ← previous: [Myth check: do lemmings jump off cliffs?, exam 1](https://md.mova.elamur.ai/free/en/corpora/questions/biology/150-myth-check-do-lemmings-jump-off-cliffs/e1/)
- next →: [Myth check: do lemmings jump off cliffs?, exam 3](https://md.mova.elamur.ai/free/en/corpora/questions/biology/150-myth-check-do-lemmings-jump-off-cliffs/e3/)
- ↑ back to [Myth check: do lemmings jump off cliffs?](https://md.mova.elamur.ai/free/en/corpora/questions/biology/150-myth-check-do-lemmings-jump-off-cliffs/)