---
title: Identify the principal reason for which the use of bright screens be… — Sleep and the body clock · tree and pragmatics
description: Identify the principal reason for which the use of bright screens before sleep delays its onset. Exam question 3 of lesson 127 «Sleep and the body clock» 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.
---

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# Exam question 3 · Sleep and the body clock

<!-- .ven lang=en -->
Identify the principal reason for which the use of bright screens before sleep delays its onset.

<!-- .vintro -->
**Mova's choice:** option 1 · **The right answer:** option 3 · wrong ✗ · **Who acts:** you, use · **What happens:** identify, delay, use · **To what, where:** principal reason, onset, bright screens

<!-- .vabout -->
This is exam question 3 of lesson 127 «Sleep and the body clock» of the world 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/world/127-sleep-and-the-body-clock/#e3).

## The question {#question}

```conllu
# sent_id = question:world:127-sleep-and-the-body-clock:e3:1
# text = Identify the principal reason for which the use of bright screens before sleep delays its onset.
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	14	obl	_	_
7	the	the	DET	DT	Definite=Def|PronType=Art	8	det	_	_
8	use	use	NOUN	NN	Number=Sing	14	nsubj	_	_
9	of	of	ADP	IN	_	11	case	_	_
10	bright	bright	ADJ	JJ	Degree=Pos	11	amod	_	_
11	screens	screen	NOUN	NNS	Number=Plur	8	nmod	_	_
12	before	before	ADP	IN	_	13	case	_	_
13	sleep	sleep	NOUN	NN	Number=Sing	11	nmod	_	_
14	delays	delay	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	4	acl	_	_
15	its	its	PRON	PRP$	Case=Gen|Gender=Neut|Number=Sing|Person=3|Poss=Yes|PronType=Prs	16	nmod:poss	_	_
16	onset	onset	NOUN	NN	Number=Sing	14	obj	_	SpaceAfter=No
17	.	.	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 | **delay** | present | the use of bright screens before sleep | use's onset |  |  |  | for the principal reason | vn delay-53.3-1-1 «NP V»: agent=Agent onset=Source |
| 3 | **use** |  |  | bright screens before sleep |  |  |  |  | nom use «act 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.

## The options {#options}

### Option 1 · ← Mova's choice {#o1}

<!-- .ven lang=en -->
The light increases the temperature of the bedroom

```conllu
# sent_id = question:world:127-sleep-and-the-body-clock:e3:o1:1
# text = The light increases the temperature of the bedroom
1	The	the	DET	DT	Definite=Def|PronType=Art	2	det	_	_
2	light	light	NOUN	NN	Number=Sing	3	nsubj	_	_
3	increases	increase	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
4	the	the	DET	DT	Definite=Def|PronType=Art	5	det	_	_
5	temperature	temperature	NOUN	NN	Number=Sing	3	obj	_	_
6	of	of	ADP	IN	_	8	case	_	_
7	the	the	DET	DT	Definite=Def|PronType=Art	8	det	_	_
8	bedroom	bedroom	NOUN	NN	Number=Sing	5	nmod	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **increase** | present | the light | the temperature of the bedroom |  |  |  |  | vn caused\_calibratable\_cos-45.6.2-1 «NP V NP.patient»: agent=Causer temperature=Patient |

### Option 2 {#o2}

<!-- .ven lang=en -->
The screens deplete the body's reserves of energy

```conllu
# sent_id = question:world:127-sleep-and-the-body-clock:e3:o2:1
# text = The screens deplete the body's reserves of energy
1	The	the	DET	DT	Definite=Def|PronType=Art	2	det	_	_
2	screens	screen	NOUN	NNS	Number=Plur	3	nsubj	_	_
3	deplete	deplete	VERB	VBP	Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
4	the	the	DET	DT	Definite=Def|PronType=Art	5	det	_	_
5	body	body	NOUN	NN	Number=Sing	7	nmod:poss	_	SpaceAfter=No
6	's	's	PART	POS	_	5	case	_	_
7	reserves	reserve	NOUN	NNS	Number=Plur	3	obj	_	_
8	of	of	ADP	IN	_	9	case	_	_
9	energy	energy	NOUN	NN	Number=Sing	7	nmod	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **deplete** | present | the screens | the body's reserves of energy |  |  |  |  | vn deprive-10.6.2 «NP V NP»: agent=Agent reserve=Source |

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

<!-- .ven lang=en -->
The light diminishes the release of melatonin

```conllu
# sent_id = question:world:127-sleep-and-the-body-clock:e3:o3:1
# text = The light diminishes the release of melatonin
1	The	the	DET	DT	Definite=Def|PronType=Art	2	det	_	_
2	light	light	NOUN	NN	Number=Sing	3	nsubj	_	_
3	diminishes	diminish	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
4	the	the	DET	DT	Definite=Def|PronType=Art	5	det	_	_
5	release	release	NOUN	NN	Number=Sing	3	obj	_	_
6	of	of	ADP	IN	_	7	case	_	_
7	melatonin	melatonin	NOUN	NN	Number=Sing	5	nmod	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **diminish** | present | the light | the release of melatonin |  |  |  |  | vn caused\_calibratable\_cos-45.6.2-1 «NP V NP.patient»: agent=Causer release=Patient |

### Option 4 {#o4}

<!-- .ven lang=en -->
The screens emit sounds inaudible to the user

```conllu
# sent_id = question:world:127-sleep-and-the-body-clock:e3:o4:1
# text = The screens emit sounds inaudible to the user
1	The	the	DET	DT	Definite=Def|PronType=Art	2	det	_	_
2	screens	screen	NOUN	NNS	Number=Plur	3	nsubj	_	_
3	emit	emit	VERB	VBP	Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
4	sounds	sound	NOUN	NNS	Number=Plur	3	obj	_	_
5	inaudible	inaudible	ADJ	JJ	Degree=Pos	3	xcomp	_	_
6	to	to	ADP	IN	_	8	case	_	_
7	the	the	DET	DT	Definite=Def|PronType=Art	8	det	_	_
8	user	user	NOUN	NN	Number=Sing	3	obl	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **emit** | present | the screens | sounds |  |  |  | to the user; inaudible *property* | vn substance\_emission-43.4 «NP V NP»: agent=Source sound=Theme |

<!-- 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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- ← previous: [Sleep and the body clock, exam 2](https://md.mova.elamur.ai/free/en/corpora/questions/world/127-sleep-and-the-body-clock/e2/)
- next →: [Sleep and the body clock, exam 4](https://md.mova.elamur.ai/free/en/corpora/questions/world/127-sleep-and-the-body-clock/e4/)
- ↑ back to [Sleep and the body clock](https://md.mova.elamur.ai/free/en/corpora/questions/world/127-sleep-and-the-body-clock/)