---
title: Identify the principal reason for which desert temperatures may decl… — The desert: living with little water · tree and pragmatics
description: Identify the principal reason for which desert temperatures may decline below freezing during the night. Exam question 2 of lesson 5 «The desert: living with little water» 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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# Exam question 2 · The desert: living with little water

<!-- .ven lang=en -->
Identify the principal reason for which desert temperatures may decline below freezing during the night.

<!-- .vintro -->
**Mova's choice:** option 1 · **The right answer:** option 4 · wrong ✗ · **Who acts:** you, desert temperatures · **What happens:** identify, decline · **To what, where:** principal reason, freezing

<!-- .vabout -->
This is exam question 2 of lesson 5 «The desert: living with little water» 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/5-the-desert/#e2).

## The question {#question}

```conllu
# sent_id = question:biology:5-the-desert:e2:1
# text = Identify the principal reason for which desert temperatures may decline below freezing during the night.
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	reason	reason	NOUN	NN	Number=Sing	1	obj	_	_
5	for	for	ADP	IN	_	6	case	_	_
6	which	which	PRON	WDT	PronType=Rel	10	obl	_	_
7	desert	desert	NOUN	NN	Number=Sing	8	compound	_	_
8	temperatures	temperature	NOUN	NNS	Number=Plur	10	nsubj	_	_
9	may	may	AUX	MD	VerbForm=Fin	10	aux	_	_
10	decline	decline	VERB	VB	VerbForm=Inf	4	parataxis	_	_
11	below	below	ADP	IN	_	12	case	_	_
12	freezing	freezing	NOUN	NN	Number=Sing	10	obl	_	_
13	during	during	ADP	IN	_	15	case	_	_
14	the	the	DET	DT	Definite=Def|PronType=Art	15	det	_	_
15	night	night	NOUN	NN	Number=Sing	10	obl	_	SpaceAfter=No
16	.	.	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 reason |  |  |  |  | vn characterize-29.2-1-1 «NP V NP S\_ING»: agent=Agent reason=Theme |
| 2 | **decline** | may | desert temperatures |  |  | freezing | night | for the principal reason | vn calibratable\_cos-45.6.1-1 «NP.attribute V»: agent=Attribute |

<!-- .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 -->
The sand generates cold during the hours of darkness

```conllu
# sent_id = question:biology:5-the-desert:e2:o1:1
# text = The sand generates cold during the hours of darkness
1	The	the	DET	DT	Definite=Def|PronType=Art	2	det	_	_
2	sand	sand	NOUN	NN	Number=Sing	3	nsubj	_	_
3	generates	generate	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
4	cold	cold	ADJ	JJ	Degree=Pos	3	xcomp	_	_
5	during	during	ADP	IN	_	7	case	_	_
6	the	the	DET	DT	Definite=Def|PronType=Art	7	det	_	_
7	hours	hour	NOUN	NNS	Number=Plur	3	obl	_	_
8	of	of	ADP	IN	_	9	case	_	_
9	darkness	darkness	NOUN	NN	Number=Sing	7	nmod	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **generate** | present | the sand |  |  |  | hour | cold *property* | vn grow-26.2.1 «NP.patient V PP.product»: agent=Patient |

### Option 2 {#o2}

<!-- .ven lang=en -->
The Sun is positioned nearer to the Earth by day

```conllu
# sent_id = question:biology:5-the-desert:e2:o2:1
# text = The Sun is positioned nearer to the Earth by day
1	The	the	DET	DT	Definite=Def|PronType=Art	2	det	_	_
2	Sun	Sun	PROPN	NNP	Number=Sing	4	nsubj	_	_
3	is	be	AUX	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	4	aux:pass	_	_
4	positioned	position	VERB	VBN	Tense=Past|VerbForm=Part|Voice=Pass	0	root	_	_
5	nearer	near	ADJ	JJR	Degree=Cmp	4	xcomp	_	_
6	to	to	ADP	IN	_	8	case	_	_
7	the	the	DET	DT	Definite=Def|PronType=Art	8	det	_	_
8	Earth	Earth	PROPN	NNP	Number=Sing	4	obl	_	_
9	by	by	ADP	IN	_	10	case	_	_
10	day	day	NOUN	NN	Number=Sing	4	obl	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **position** | present · passive |  | the Sun |  |  | day | to the Earth; near *property* | vn put-9.1 «NP V NP ADVP»: subject=Destination |

### Option 3 {#o3}

<!-- .ven lang=en -->
Glacial winds traverse every desert nightly from the polar regions and from the mountains of the interior

<!-- fold The tree, 17 words -->
```conllu
# sent_id = question:biology:5-the-desert:e2:o3:1
# text = Glacial winds traverse every desert nightly from the polar regions and from the mountains of the interior
1	Glacial	glacial	ADJ	JJ	Degree=Pos	2	amod	_	_
2	winds	wind	NOUN	NNS	Number=Plur	3	nsubj	_	_
3	traverse	traverse	VERB	VBP	Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
4	every	every	DET	DT	PronType=Tot	5	det	_	_
5	desert	desert	NOUN	NN	Number=Sing	3	obj	_	_
6	nightly	nightly	ADV	RB	_	3	advmod	_	_
7	from	from	ADP	IN	_	10	case	_	_
8	the	the	DET	DT	Definite=Def|PronType=Art	10	det	_	_
9	polar	polar	ADJ	JJ	Degree=Pos	10	amod	_	_
10	regions	region	NOUN	NNS	Number=Plur	3	obl	_	_
11	and	and	CCONJ	CC	_	14	cc	_	_
12	from	from	ADP	IN	_	14	case	_	_
13	the	the	DET	DT	Definite=Def|PronType=Art	14	det	_	_
14	mountains	mountain	NOUN	NNS	Number=Plur	10	conj	_	_
15	of	of	ADP	IN	_	17	case	_	_
16	the	the	DET	DT	Definite=Def|PronType=Art	17	det	_	_
17	interior	interior	NOUN	NN	Number=Sing	14	nmod	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **traverse** | present | Glacial winds | every desert |  | the polar regions and the mountains of the interior |  | nightly *property* | vn contiguous\_location-47.8 «NP V NP»: agent=Theme desert=Co-Theme |

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

<!-- .ven lang=en -->
In the absence of atmospheric moisture and cloud, the heat of the ground escapes freely into space

<!-- fold The tree, 17 words -->
```conllu
# sent_id = question:biology:5-the-desert:e2:o4:1
# text = In the absence of atmospheric moisture and cloud, the heat of the ground escapes freely into space
1	In	in	ADP	IN	_	3	case	_	_
2	the	the	DET	DT	Definite=Def|PronType=Art	3	det	_	_
3	absence	absence	NOUN	NN	Number=Sing	15	obl	_	_
4	of	of	ADP	IN	_	6	case	_	_
5	atmospheric	atmospheric	NOUN	NN	Number=Sing	6	compound	_	_
6	moisture	moisture	NOUN	NN	Number=Sing	3	nmod	_	_
7	and	and	CCONJ	CC	_	8	cc	_	_
8	cloud	cloud	NOUN	NN	Number=Sing	6	conj	_	SpaceAfter=No
9	,	,	PUNCT	,	_	3	punct	_	_
10	the	the	DET	DT	Definite=Def|PronType=Art	11	det	_	_
11	heat	heat	NOUN	NN	Number=Sing	15	nsubj	_	_
12	of	of	ADP	IN	_	14	case	_	_
13	the	the	DET	DT	Definite=Def|PronType=Art	14	det	_	_
14	ground	ground	NOUN	NN	Number=Sing	11	nmod	_	_
15	escapes	escape	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
16	freely	freely	ADV	RB	_	15	advmod	_	_
17	into	into	ADP	IN	_	18	case	_	_
18	space	space	NOUN	NN	Number=Sing	15	obl	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **escape** | present | the heat of the ground |  |  | the absence of atmospheric moisture and cloud |  | into space; freely *property* | vn escape-51.1-1-1 «NP V PP.initial\_location»: agent=Theme into space=Initial\_Location |
| 2 | **absent** |  |  | atmospheric moisture and cloud |  |  |  |  | nom absence «state transitive»: of=patient |
| 3 | **heat** |  | the ground |  |  |  |  |  | nom heat «phenomenon intransitive»: of=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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