---
title: Sea otters return to a coast. What happens to the kelp forest over t… — Balance in a food web · tree and pragmatics
description: Sea otters return to a coast. What happens to the kelp forest over the years? Test 10 · ★★★ of lesson 30 «Balance in a food web» of the world course of Mova's primary school, with the dependency tree and pragmatics of the question and of each option; Mova's choice was wrong.
---

<!-- md -->
[Mova](https://md.mova.elamur.ai/free/en/) · [this page in HTML](https://mova.elamur.ai/free/en/corpora/questions/world/30-balance-in-food-webs/t10/)

<!-- crumbs -->
[home](https://md.mova.elamur.ai/free/en/) / [corpora](https://md.mova.elamur.ai/free/en/corpora/) / [questions](https://md.mova.elamur.ai/free/en/corpora/questions/) / [World](https://md.mova.elamur.ai/free/en/corpora/questions/world/) / [Balance in a food web](https://md.mova.elamur.ai/free/en/corpora/questions/world/30-balance-in-food-webs/) / t10

# Test 10 · ★★★ · Balance in a food web

<!-- .ven lang=en -->
Sea otters return to a coast. What happens to the kelp forest over the years?

<!-- .vintro -->
**Mova's choice:** option 3 · **The right answer:** option 2 · wrong ✗ · **Who acts:** Sea otters · **What happens:** return, happen

<!-- .vabout -->
This is test 10 · ★★★ of lesson 30 «Balance in a food web» of the world course of Mova's primary school. 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/world/30-balance-in-food-webs/#t10).

## The question {#question}

<!-- .note -->
*Sentence 1:* Sea otters return to a coast.

```conllu
# sent_id = question:world:30-balance-in-food-webs:t10:1
# text = Sea otters return to a coast.
1	Sea	sea	NOUN	NN	Number=Sing	2	compound	_	_
2	otters	otter	NOUN	NNS	Number=Plur	3	nsubj	_	_
3	return	return	VERB	VBP	Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
4	to	to	ADP	IN	_	6	case	_	_
5	a	a	DET	DT	Definite=Ind|PronType=Art	6	det	_	_
6	coast	coast	NOUN	NN	Number=Sing	3	obl	_	SpaceAfter=No
7	.	.	PUNCT	.	_	3	punct	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **return** | present | Sea otters |  |  |  |  | to a coast *result* | vn convert-26.6.2-1 «NP V S\_ING»: agent=Patient to coast=Result |

<!-- .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.

<!-- .note -->
*Sentence 2:* What happens to the kelp forest over the years?

```conllu
# sent_id = question:world:30-balance-in-food-webs:t10:2
# text = What happens to the kelp forest over the years?
1	What	what	PRON	WP	PronType=Int	2	nsubj	_	_
2	happens	happen	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
3	to	to	ADP	IN	_	6	case	_	_
4	the	the	DET	DT	Definite=Def|PronType=Art	6	det	_	_
5	kelp	kelp	NOUN	NN	Number=Sing	6	compound	_	_
6	forest	forest	NOUN	NN	Number=Sing	2	obl	_	_
7	over	over	ADP	IN	_	9	case	_	_
8	the	the	DET	DT	Definite=Def|PronType=Art	9	det	_	_
9	years	year	NOUN	NNS	Number=Plur	2	obl	_	SpaceAfter=No
10	?	?	PUNCT	.	_	2	punct	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **happen** | present |  |  |  |  | year | to the kelp forest | vn occur-48.3-1 «NP V»: agent=Theme |

## The options {#options}

### Option 1 {#o1}

<!-- .ven lang=en -->
It is replaced by bare sand and stones

```conllu
# sent_id = question:world:30-balance-in-food-webs:t10:o1:1
# text = It is replaced by bare sand and stones
1	It	it	PRON	PRP	Case=Nom|Gender=Neut|Number=Sing|Person=3|PronType=Prs	3	nsubj:pass	_	_
2	is	be	AUX	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	3	aux:pass	_	_
3	replaced	replace	VERB	VBN	Tense=Past|VerbForm=Part|Voice=Pass	0	root	_	_
4	by	by	ADP	IN	_	6	case	_	_
5	bare	bare	ADJ	JJ	Degree=Pos	6	amod	_	_
6	sand	sand	NOUN	NN	Number=Sing	3	obl	_	_
7	and	and	CCONJ	CC	_	8	cc	_	_
8	stones	stone	NOUN	NNS	Number=Plur	6	conj	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **replace** | present · passive | bare sand and stones | It |  |  |  |  | vn substitute-13.6.2-1 «NP V NP»: agent=Theme subject=Co-Theme |

### Option 2 · ✓ the right answer {#o2}

<!-- .ven lang=en -->
It grows back as urchins become fewer

```conllu
# sent_id = question:world:30-balance-in-food-webs:t10:o2:1
# text = It grows back as urchins become fewer
1	It	it	PRON	PRP	Case=Nom|Gender=Neut|Number=Sing|Person=3|PronType=Prs	2	nsubj	_	_
2	grows	grow	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
3	back	back	ADV	RB	_	2	advmod	_	_
4	as	as	SCONJ	IN	_	6	mark	_	_
5	urchins	urchin	NOUN	NNS	Number=Plur	6	nsubj	_	_
6	become	become	VERB	VBP	Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin	2	advcl	_	_
7	fewer	few	ADJ	JJR	Degree=Cmp	6	xcomp	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **grow back** | present | It |  |  |  |  |  | vn appear-48.1.1 «NP V»: agent=Theme |
| 2 | **become** | present | urchins |  |  |  |  | few *property* | vn become-109.1-1-1 «NP V PP.attribute»: agent=Patient |

### Option 3 · ← Mova's choice {#o3}

<!-- .ven lang=en -->
It disappears completely as the otters eat the kelp

```conllu
# sent_id = question:world:30-balance-in-food-webs:t10:o3:1
# text = It disappears completely as the otters eat the kelp
1	It	it	PRON	PRP	Case=Nom|Gender=Neut|Number=Sing|Person=3|PronType=Prs	2	nsubj	_	_
2	disappears	disappear	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
3	completely	completely	ADV	RB	_	2	advmod	_	_
4	as	as	SCONJ	IN	_	7	mark	_	_
5	the	the	DET	DT	Definite=Def|PronType=Art	6	det	_	_
6	otters	otter	NOUN	NNS	Number=Plur	7	nsubj	_	_
7	eat	eat	VERB	VBP	Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin	2	advcl	_	_
8	the	the	DET	DT	Definite=Def|PronType=Art	9	det	_	_
9	kelp	kelp	NOUN	NN	Number=Sing	7	obj	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **disappear** | present | It |  |  |  |  | completely *property* | vn disappearance-48.2-1 «NP V»: agent=Theme |
| 2 | **eat** | present | the otters | the kelp |  |  |  |  | vn eat-39.1-1 «NP V NP»: agent=Agent kelp=Patient |

### Option 4 {#o4}

<!-- .ven lang=en -->
It stays exactly the same as it was before

```conllu
# sent_id = question:world:30-balance-in-food-webs:t10:o4:1
# text = It stays exactly the same as it was before
1	It	it	PRON	PRP	Case=Nom|Gender=Neut|Number=Sing|Person=3|PronType=Prs	2	nsubj	_	_
2	stays	stay	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
3	exactly	exactly	ADV	RB	_	5	advmod	_	_
4	the	the	DET	DT	Definite=Def|PronType=Art	5	det	_	_
5	same	same	ADJ	JJ	Degree=Pos	2	xcomp	_	_
6	as	as	SCONJ	IN	_	9	mark	_	_
7	it	it	PRON	PRP	Case=Nom|Gender=Neut|Number=Sing|Person=3|PronType=Prs	9	nsubj	_	_
8	was	be	AUX	VBD	Mood=Ind|Number=Sing|Person=3|Tense=Past|VerbForm=Fin	9	cop	_	_
9	before	before	ADV	RB	_	2	advmod	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **stay** | present | It |  |  |  |  | same *property* | vn exist-47.1 «NP V»: agent=Theme |
| 2 | **is** | past | it |  |  |  |  | before *property* | tree rules |

<!-- div src -->

**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.

<!-- /div -->

<!-- pn -->
- ← previous: [Balance in a food web, test 9](https://md.mova.elamur.ai/free/en/corpora/questions/world/30-balance-in-food-webs/t9/)
- next →: [Balance in a food web, test 11](https://md.mova.elamur.ai/free/en/corpora/questions/world/30-balance-in-food-webs/t11/)
- ↑ back to [Balance in a food web](https://md.mova.elamur.ai/free/en/corpora/questions/world/30-balance-in-food-webs/)