---
title: Why do so many animals swim up only at night and not by day? — The twilight zone: barreleyes, lantern… · tree and pragmatics
description: Why do so many animals swim up only at night and not by day? Test 2 · ★ of lesson 175 «The twilight zone: barreleyes, lanternfish and the biggest daily journey on Earth» of the biology course of Mova's primary school, with the dependency tree and pragmatics of the question and of each option; Mova's
---

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# Test 2 · ★ · The twilight zone: barreleyes, lanternfish and the biggest…

<!-- .ven lang=en -->
Why do so many animals swim up only at night and not by day?

<!-- .vintro -->
**Mova's choice:** option 2 · **The right answer:** option 3 · wrong ✗ · **Who acts:** many animals · **What happens:** swim up

<!-- .vabout -->
This is test 2 · ★ of lesson 175 «The twilight zone: barreleyes, lanternfish and the biggest daily journey on Earth» 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/175-the-twilight-zone-barreleyes-lanternfish-and-the-biggest-daily-journey-on-earth/#t2).

## The question {#question}

```conllu
# sent_id = question:biology:175-the-twilight-zone-barreleyes-lanternfish-and-the-biggest-daily-journey-on-earth:t2:1
# text = Why do so many animals swim up only at night and not by day?
1	Why	why	ADV	WRB	PronType=Int	6	advmod	_	_
2	do	do	AUX	VBP	Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin	6	aux	_	_
3	so	so	ADV	RB	_	6	advmod	_	_
4	many	many	ADJ	JJ	Degree=Pos	5	amod	_	_
5	animals	animal	NOUN	NNS	Number=Plur	6	nsubj	_	_
6	swim	swim	VERB	VBP	Mood=Ind|Number=Sing|Person=1|Tense=Pres|VerbForm=Fin	0	root	_	_
7	up	up	ADP	RP	_	6	compound:prt	_	_
8	only	only	ADV	RB	_	10	advmod	_	_
9	at	at	ADP	IN	_	10	case	_	_
10	night	night	NOUN	NN	Number=Sing	6	obl	_	_
11	and	and	CCONJ	CC	_	14	cc	_	_
12	not	not	PART	RB	Polarity=Neg	14	advmod	_	_
13	by	by	ADP	IN	_	14	case	_	_
14	day	day	NOUN	NN	Number=Sing	10	conj	_	SpaceAfter=No
15	?	?	PUNCT	.	_	6	punct	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **swim up** | present · do-support | many animals |  |  |  | night |  | vn run-51.3.2-1 «NP V»: agent=Theme |

<!-- .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 {#o1}

<!-- .ven lang=en -->
The surface water is colder by day

```conllu
# sent_id = question:biology:175-the-twilight-zone-barreleyes-lanternfish-and-the-biggest-daily-journey-on-earth:t2:o1:1
# text = The surface water is colder by day
1	The	the	DET	DT	Definite=Def|PronType=Art	3	det	_	_
2	surface	surface	NOUN	NN	Number=Sing	3	compound	_	_
3	water	water	NOUN	NN	Number=Sing	5	nsubj	_	_
4	is	be	AUX	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	5	cop	_	_
5	colder	cold	ADJ	JJR	Degree=Cmp	0	root	_	_
6	by	by	ADP	IN	_	7	case	_	_
7	day	day	NOUN	NN	Number=Sing	5	obl	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **is** | present | the surface water |  |  |  | day | cold *property* | tree rules |

### Option 2 · ← Mova's choice {#o2}

<!-- .ven lang=en -->
Sunlight burns them in seconds

```conllu
# sent_id = question:biology:175-the-twilight-zone-barreleyes-lanternfish-and-the-biggest-daily-journey-on-earth:t2:o2:1
# text = Sunlight burns them in seconds
1	Sunlight	sunlight	NOUN	NN	Number=Sing	2	nsubj	_	_
2	burns	burn	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
3	them	they	PRON	PRP	Case=Acc|Number=Plur|Person=3|PronType=Prs	2	obj	_	_
4	in	in	ADP	IN	_	5	case	_	_
5	seconds	second	NOUN	NNS	Number=Plur	2	obl	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **burn** | present | Sunlight | them *= they* |  |  | second |  | vn light\_emission-43.1 «NP V NP.theme»: agent=Agent they=Theme |

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

<!-- .ven lang=en -->
In the dark it is harder for hunters near the surface to see them

```conllu
# sent_id = question:biology:175-the-twilight-zone-barreleyes-lanternfish-and-the-biggest-daily-journey-on-earth:t2:o3:1
# text = In the dark it is harder for hunters near the surface to see them
1	In	in	ADP	IN	_	3	case	_	_
2	the	the	DET	DT	Definite=Def|PronType=Art	3	det	_	_
3	dark	dark	NOUN	NN	Number=Sing	6	obl	_	_
4	it	it	PRON	PRP	Case=Nom|Gender=Neut|Number=Sing|Person=3|PronType=Prs	6	nsubj	_	_
5	is	be	AUX	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	6	cop	_	_
6	harder	hard	ADJ	JJR	Degree=Cmp	0	root	_	_
7	for	for	ADP	IN	_	8	case	_	_
8	hunters	hunter	NOUN	NNS	Number=Plur	6	obl	_	_
9	near	near	ADP	IN	_	11	case	_	_
10	the	the	DET	DT	Definite=Def|PronType=Art	11	det	_	_
11	surface	surface	NOUN	NN	Number=Sing	8	nmod	_	_
12	to	to	PART	TO	_	13	mark	_	_
13	see	see	VERB	VB	VerbForm=Inf	6	csubj	_	_
14	them	they	PRON	PRP	Case=Acc|Number=Plur|Person=3|PronType=Prs	13	obj	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **is** | present | it |  |  | the dark |  | for hunters near the surface; hard *property* | tree rules |
| 2 | **see** | to-infinitive |  | hunters *= hunter* |  |  |  |  | vn comprehend-87.2-1-1 «NP V NP»: agent=Experiencer they=Stimulus |

### Option 4 {#o4}

<!-- .ven lang=en -->
They cannot swim during the day, so they lie still on the bottom till dark

<!-- fold The tree, 16 words -->
```conllu
# sent_id = question:biology:175-the-twilight-zone-barreleyes-lanternfish-and-the-biggest-daily-journey-on-earth:t2:o4:1
# text = They cannot swim during the day, so they lie still on the bottom till dark
1	They	they	PRON	PRP	Case=Nom|Number=Plur|Person=3|PronType=Prs	4	nsubj	_	_
2	can	can	AUX	MD	VerbForm=Fin	4	aux	_	SpaceAfter=No
3	not	not	PART	RB	Polarity=Neg	4	advmod	_	_
4	swim	swim	VERB	VB	VerbForm=Inf	0	root	_	_
5	during	during	ADP	IN	_	7	case	_	_
6	the	the	DET	DT	Definite=Def|PronType=Art	7	det	_	_
7	day	day	NOUN	NN	Number=Sing	4	obl	_	SpaceAfter=No
8	,	,	PUNCT	,	_	11	punct	_	_
9	so	so	ADV	RB	_	11	advmod	_	_
10	they	they	PRON	PRP	Case=Nom|Number=Plur|Person=3|PronType=Prs	11	nsubj	_	_
11	lie	lie	VERB	VBP	Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin	4	parataxis	_	_
12	still	still	ADV	RB	_	11	advmod	_	_
13	on	on	ADP	IN	_	15	case	_	_
14	the	the	DET	DT	Definite=Def|PronType=Art	15	det	_	_
15	bottom	bottom	NOUN	NN	Number=Sing	11	obl	_	_
16	till	till	ADP	IN	_	17	case	_	_
17	dark	dark	ADJ	JJ	Degree=Pos	4	obl	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **not** **swim** | can | They |  |  |  | till dark; day |  | vn run-51.3.2-1 «NP V»: agent=Theme |
| 2 | **lie** | present | they |  |  | the bottom | still |  | vn assuming\_position-50 «NP V PP.location»: agent=Agent on bottom=Location |

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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: [The twilight zone: barreleyes, lantern…, test 1](https://md.mova.elamur.ai/free/en/corpora/questions/biology/175-the-twilight-zone-barreleyes-lanternfish-and-the-biggest-daily-journey-on-earth/t1/)
- next →: [The twilight zone: barreleyes, lantern…, test 3](https://md.mova.elamur.ai/free/en/corpora/questions/biology/175-the-twilight-zone-barreleyes-lanternfish-and-the-biggest-daily-journey-on-earth/t3/)
- ↑ back to [The twilight zone: barreleyes, lanternfish and the biggest daily journey on Earth](https://md.mova.elamur.ai/free/en/corpora/questions/biology/175-the-twilight-zone-barreleyes-lanternfish-and-the-biggest-daily-journey-on-earth/)