---
title: Ascertain the reason for which the Mariana snailfish withstands the… — Vents and trenches: tubeworms, iron sn… · tree and pragmatics
description: Ascertain the reason for which the Mariana snailfish withstands the pressure prevailing at its depth. Exam question 4 of lesson 177 «Vents and trenches: tubeworms, iron snails, the Challenger Deep and life without sunlight» of the biology course of Mova's primary school, with the dependency tree and
---

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# Exam question 4 · Vents and trenches: tubeworms, iron snails, the Challenger…

<!-- .ven lang=en -->
Ascertain the reason for which the Mariana snailfish withstands the pressure prevailing at its depth.

<!-- .vintro -->
**Mova's choice:** option 1 · **The right answer:** option 4 · wrong ✗ · **Who acts:** you, Mariana snailfish, pressure · **What happens:** ascertain, withstand, prevail · **To what, where:** reason, pressure, depth

<!-- .vabout -->
This is exam question 4 of lesson 177 «Vents and trenches: tubeworms, iron snails, the Challenger Deep and life without sunlight» 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/177-vents-and-trenches-tubeworms-iron-snails-the-challenger-deep-and-life-without-sunlight/#e4).

## The question {#question}

```conllu
# sent_id = question:biology:177-vents-and-trenches-tubeworms-iron-snails-the-challenger-deep-and-life-without-sunlight:e4:1
# text = Ascertain the reason for which the Mariana snailfish withstands the pressure prevailing at its depth.
1	Ascertain	ascertain	VERB	VB	Mood=Imp|VerbForm=Fin	0	root	_	_
2	the	the	DET	DT	Definite=Def|PronType=Art	3	det	_	_
3	reason	reason	NOUN	NN	Number=Sing	1	obj	_	_
4	for	for	ADP	IN	_	5	case	_	_
5	which	which	PRON	WDT	PronType=Rel	9	obl	_	_
6	the	the	DET	DT	Definite=Def|PronType=Art	8	det	_	_
7	Mariana	Mariana	PROPN	NNP	Number=Sing	8	compound	_	_
8	snailfish	snailfish	NOUN	NN	Number=Sing	9	nsubj	_	_
9	withstands	withstand	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	3	acl:relcl	_	_
10	the	the	DET	DT	Definite=Def|PronType=Art	11	det	_	_
11	pressure	pressure	NOUN	NN	Number=Sing	9	obj	_	_
12	prevailing	prevail	VERB	VBG	VerbForm=Ger	11	acl	_	_
13	at	at	ADP	IN	_	15	case	_	_
14	its	its	PRON	PRP$	Case=Gen|Gender=Neut|Number=Sing|Person=3|Poss=Yes|PronType=Prs	15	nmod:poss	_	_
15	depth	depth	NOUN	NN	Number=Sing	12	obl	_	SpaceAfter=No
16	.	.	PUNCT	.	_	1	punct	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **ascertain** | imperative | you *not said here* | the reason |  |  |  |  | vn discover-84 «NP V NP»: agent=Agent reason=Topic |
| 2 | **withstand** | present | the Mariana snailfish | the pressure |  |  |  | for the reason | tree rules |
| 3 | **prevail** | gerund | the pressure *not said here* |  |  | snailfish's depth |  |  | vn exist-47.1 «NP V PP.location»: agent=Theme at depth=Location |

<!-- .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 -->
It retains a large volume of air within its body

```conllu
# sent_id = question:biology:177-vents-and-trenches-tubeworms-iron-snails-the-challenger-deep-and-life-without-sunlight:e4:o1:1
# text = It retains a large volume of air within its body
1	It	it	PRON	PRP	Case=Nom|Gender=Neut|Number=Sing|Person=3|PronType=Prs	2	nsubj	_	_
2	retains	retain	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
3	a	a	DET	DT	Definite=Ind|PronType=Art	5	det	_	_
4	large	large	ADJ	JJ	Degree=Pos	5	amod	_	_
5	volume	volume	NOUN	NN	Number=Sing	2	obj	_	_
6	of	of	ADP	IN	_	7	case	_	_
7	air	air	NOUN	NN	Number=Sing	5	nmod	_	_
8	within	within	ADP	IN	_	10	case	_	_
9	its	its	PRON	PRP$	Case=Gen|Gender=Neut|Number=Sing|Person=3|Poss=Yes|PronType=Prs	10	nmod:poss	_	_
10	body	body	NOUN	NN	Number=Sing	2	obl	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **retain** | present | It | a large volume of air |  |  |  | within air's body | tree rules |

### Option 2 {#o2}

<!-- .ven lang=en -->
It ascends to shallow water daily

```conllu
# sent_id = question:biology:177-vents-and-trenches-tubeworms-iron-snails-the-challenger-deep-and-life-without-sunlight:e4:o2:1
# text = It ascends to shallow water daily
1	It	it	PRON	PRP	Case=Nom|Gender=Neut|Number=Sing|Person=3|PronType=Prs	2	nsubj	_	_
2	ascends	ascend	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
3	to	to	PART	TO	_	4	mark	_	_
4	shallow	shallow	ADJ	JJ	Degree=Pos	5	amod	_	_
5	water	water	NOUN	NN	Number=Sing	2	obj	_	_
6	daily	daily	ADV	RB	_	2	advmod	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **ascend** | present | It | shallow water |  |  |  | daily *property* | vn escape-51.1-1-3 «NP V NP»: agent=Theme water=Trajectory |

### Option 3 {#o3}

<!-- .ven lang=en -->
Its body is enclosed in armour of iron

```conllu
# sent_id = question:biology:177-vents-and-trenches-tubeworms-iron-snails-the-challenger-deep-and-life-without-sunlight:e4:o3:1
# text = Its body is enclosed in armour of iron
1	Its	its	PRON	PRP$	Case=Gen|Gender=Neut|Number=Sing|Person=3|Poss=Yes|PronType=Prs	2	nmod:poss	_	_
2	body	body	NOUN	NN	Number=Sing	4	nsubj:pass	_	_
3	is	be	AUX	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	4	aux:pass	_	_
4	enclosed	enclose	VERB	VBN	Tense=Past|VerbForm=Part|Voice=Pass	0	root	_	_
5	in	in	ADP	IN	_	6	case	_	_
6	armour	armour	NOUN	NN	Number=Sing	4	obl	_	_
7	of	of	ADP	IN	_	8	case	_	_
8	iron	iron	NOUN	NN	Number=Sing	6	nmod	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **enclose** | present · passive |  | Its body |  | armour of iron |  |  | vn contiguous\_location-47.8 «NP V NP»: subject=Co-Theme |

### Option 4 · ✓ the right answer {#o4}

<!-- .ven lang=en -->
Its skeleton is soft and its tissues are largely water

```conllu
# sent_id = question:biology:177-vents-and-trenches-tubeworms-iron-snails-the-challenger-deep-and-life-without-sunlight:e4:o4:1
# text = Its skeleton is soft and its tissues are largely water
1	Its	its	PRON	PRP$	Case=Gen|Gender=Neut|Number=Sing|Person=3|Poss=Yes|PronType=Prs	2	nmod:poss	_	_
2	skeleton	skeleton	NOUN	NN	Number=Sing	4	nsubj	_	_
3	is	be	AUX	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	4	cop	_	_
4	soft	soft	ADJ	JJ	Degree=Pos	0	root	_	_
5	and	and	CCONJ	CC	_	10	cc	_	_
6	its	its	PRON	PRP$	Case=Gen|Gender=Neut|Number=Sing|Person=3|Poss=Yes|PronType=Prs	7	nmod:poss	_	_
7	tissues	tissue	NOUN	NNS	Number=Plur	10	nsubj	_	_
8	are	be	AUX	VBP	Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin	10	cop	_	_
9	largely	largely	ADV	RB	_	10	advmod	_	_
10	water	water	NOUN	NN	Number=Sing	4	conj	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **is** | present | Its skeleton |  |  |  |  | soft *property* | tree rules |
| 2 | **is a** | present | skeleton's tissues | water |  |  |  | largely *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 -->

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