---
title: Divers pull hundreds of crown-of-thorns starfish off a reef. Why? — Coral reef builders: polyps, bleaching… · tree and pragmatics
description: Divers pull hundreds of crown-of-thorns starfish off a reef. Why? Test 11 · ★ of lesson 172 «Coral reef builders: polyps, bleaching, sand from parrotfish and giant clams» of the biology course of Mova's primary school, with the dependency tree and pragmatics of the question and of each option; Mova'
---

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# Test 11 · ★ · Coral reef builders: polyps, bleaching, sand from parrotfi…

<!-- .ven lang=en -->
Divers pull hundreds of crown-of-thorns starfish off a reef. Why?

<!-- .vintro -->
**Mova's choice:** option 2 · **The right answer:** option 2 · right ✓ · **Who acts:** Divers · **What happens:** pull, crown · **To what, where:** hundreds, reef, thorns

<!-- .vabout -->
This is test 11 · ★ of lesson 172 «Coral reef builders: polyps, bleaching, sand from parrotfish and giant clams» of the biology 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/biology/172-coral-reef-builders-polyps-bleaching-sand-from-parrotfish-and-giant-clams/#t11).

## The question {#question}

<!-- .note -->
*Sentence 1:* Divers pull hundreds of crown-of-thorns starfish off a reef.

```conllu
# sent_id = question:biology:172-coral-reef-builders-polyps-bleaching-sand-from-parrotfish-and-giant-clams:t11:1
# text = Divers pull hundreds of crown-of-thorns starfish off a reef.
1	Divers	diver	NOUN	NNS	Number=Plur	2	nsubj	_	_
2	pull	pull	VERB	VBP	Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
3	hundreds	hundred	NOUN	NNS	Number=Plur	2	obj	_	_
4	of	of	ADP	IN	_	10	case	_	_
5	crown	crown	NOUN	NN	Number=Sing	10	compound	_	SpaceAfter=No
6	-	-	PUNCT	HYPH	_	9	punct	_	SpaceAfter=No
7	of	of	ADP	IN	_	9	case	_	SpaceAfter=No
8	-	-	PUNCT	HYPH	_	7	punct	_	SpaceAfter=No
9	thorns	thorn	NOUN	NNS	Number=Plur	5	nmod	_	_
10	starfish	starfish	NOUN	NN	Number=Sing	3	nmod	_	_
11	off	off	ADP	IN	_	13	case	_	_
12	a	a	DET	DT	Definite=Ind|PronType=Art	13	det	_	_
13	reef	reef	NOUN	NN	Number=Sing	2	obl	_	SpaceAfter=No
14	.	.	PUNCT	.	_	2	punct	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **pull** | present | Divers | hundreds of crown starfish |  | a reef |  |  | vn carry-11.4 «NP V NP PP.initial\_location»: agent=Agent hundred=Theme off reef=Initial\_Location |
| 2 | **crown** |  |  | thorns |  |  |  |  | nom crown «communication 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.

<!-- .note -->
*Sentence 2:* Why?

```conllu
# sent_id = question:biology:172-coral-reef-builders-polyps-bleaching-sand-from-parrotfish-and-giant-clams:t11:2
# text = Why?
1	Why	why	ADV	WRB	PronType=Int	0	root	_	SpaceAfter=No
2	?	?	PUNCT	.	_	1	punct	_	_
```

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

## The options {#options}

### Option 1 {#o1}

<!-- .ven lang=en -->
The starfish block out the sunlight that the reef fish need to see

```conllu
# sent_id = question:biology:172-coral-reef-builders-polyps-bleaching-sand-from-parrotfish-and-giant-clams:t11:o1:1
# text = The starfish block out the sunlight that the reef fish need to see
1	The	the	DET	DT	Definite=Def|PronType=Art	2	det	_	_
2	starfish	starfish	NOUN	NNS	Number=Plur	3	nsubj	_	_
3	block	block	VERB	VBP	Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
4	out	out	ADP	RP	_	3	compound:prt	_	_
5	the	the	DET	DT	Definite=Def|PronType=Art	6	det	_	_
6	sunlight	sunlight	NOUN	NN	Number=Sing	3	obj	_	_
7	that	that	SCONJ	IN	_	11	mark	_	_
8	the	the	DET	DT	Definite=Def|PronType=Art	9	det	_	_
9	reef	reef	NOUN	NN	Number=Sing	10	compound	_	_
10	fish	fish	NOUN	NNS	Number=Plur	11	nsubj	_	_
11	need	need	VERB	VBP	Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin	3	advcl	_	_
12	to	to	PART	TO	_	13	mark	_	_
13	see	see	VERB	VB	VerbForm=Inf	11	xcomp	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **block out** | present | the starfish | the sunlight |  |  |  |  | vn forbid-64.4-1 «NP V NP»: agent=Causer sunlight=Theme |
| 2 | **need** | present | reef fish |  |  |  |  |  | vn want-32.1-1-1 «NP V NP S\_INF»: agent=Pivot clause=Theme |
| 3 | **see** *not said to happen* | to-infinitive | reef fish *not said here* |  |  |  |  |  | vn comprehend-87.2-1-1 «NP V»: agent=Experiencer |

### Option 2 · ← Mova's choice · ✓ the right answer {#o2}

<!-- .ven lang=en -->
The starfish come in huge numbers and eat the living coral

```conllu
# sent_id = question:biology:172-coral-reef-builders-polyps-bleaching-sand-from-parrotfish-and-giant-clams:t11:o2:1
# text = The starfish come in huge numbers and eat the living coral
1	The	the	DET	DT	Definite=Def|PronType=Art	2	det	_	_
2	starfish	starfish	NOUN	NNS	Number=Plur	3	nsubj	_	_
3	come	come	VERB	VBP	Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
4	in	in	ADP	IN	_	6	case	_	_
5	huge	huge	ADJ	JJ	Degree=Pos	6	amod	_	_
6	numbers	number	NOUN	NNS	Number=Plur	3	obl	_	_
7	and	and	CCONJ	CC	_	8	cc	_	_
8	eat	eat	VERB	VBP	Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin	3	conj	_	_
9	the	the	DET	DT	Definite=Def|PronType=Art	11	det	_	_
10	living	living	NOUN	NN	Number=Sing	11	compound	_	_
11	coral	coral	NOUN	NN	Number=Sing	8	obj	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **come** | present | the starfish |  |  | huge numbers |  |  | vn appear-48.1.1 «NP V PP.location»: agent=Theme in number=Location |
| 2 | **eat** | present | the starfish *not said here* | the living coral |  |  |  |  | vn eat-39.1-1 «NP V NP»: agent=Agent coral=Patient |

### Option 3 {#o3}

<!-- .ven lang=en -->
They want to eat them for dinner

```conllu
# sent_id = question:biology:172-coral-reef-builders-polyps-bleaching-sand-from-parrotfish-and-giant-clams:t11:o3:1
# text = They want to eat them for dinner
1	They	they	PRON	PRP	Case=Nom|Number=Plur|Person=3|PronType=Prs	2	nsubj	_	_
2	want	want	VERB	VBP	Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
3	to	to	PART	TO	_	4	mark	_	_
4	eat	eat	VERB	VB	VerbForm=Inf	2	xcomp	_	_
5	them	they	PRON	PRP	Case=Acc|Number=Plur|Person=3|PronType=Prs	4	obj	_	_
6	for	for	ADP	IN	_	7	case	_	_
7	dinner	dinner	NOUN	NN	Number=Sing	4	obl	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **want** | present | They |  |  |  |  |  | vn want-32.1-1-1 «NP V NP S\_INF»: agent=Pivot clause=Theme |
| 2 | **eat** *not said to happen* | to-infinitive | They *not said here* | them *= they* |  |  |  | for dinner | vn eat-39.1-1 «NP V NP»: agent=Agent they=Patient |

### Option 4 {#o4}

<!-- .ven lang=en -->
Starfish are endangered and need saving by divers

```conllu
# sent_id = question:biology:172-coral-reef-builders-polyps-bleaching-sand-from-parrotfish-and-giant-clams:t11:o4:1
# text = Starfish are endangered and need saving by divers
1	Starfish	starfish	NOUN	NNS	Number=Plur	3	nsubj	_	_
2	are	be	AUX	VBP	Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin	3	cop	_	_
3	endangered	endangered	ADJ	JJ	Degree=Pos	0	root	_	_
4	and	and	CCONJ	CC	_	5	cc	_	_
5	need	need	VERB	VBP	Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin	3	conj	_	_
6	saving	save	VERB	VBG	VerbForm=Ger	5	xcomp	_	_
7	by	by	ADP	IN	_	8	case	_	_
8	divers	diver	NOUN	NNS	Number=Plur	6	obl	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **is** | present | Starfish |  |  |  |  | endangered *property* | tree rules |
| 2 | **need** | present | Starfish *not said here* |  |  |  |  |  | vn want-32.1-1-1 «NP V S\_ING»: agent=Pivot clause=Theme |
| 3 | **save** *not said to happen* | gerund | Starfish *not said here* |  |  |  |  | by divers | vn get-13.5.1-1 «NP V NP»: agent=Agent |

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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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