---
title: It is given that an interval of nine seconds elapses between a flash… — Thunder, sirens and how fast sound tra… · tree and pragmatics
description: It is given that an interval of nine seconds elapses between a flash and the ensuing thunder. Ascertain the approximate distance of the discharge. Exam question 2 of lesson 18 «Thunder, sirens and how fast sound travels» of the physics course of Mova's primary school, with the dependency tree and pr
---

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# Exam question 2 · Thunder, sirens and how fast sound travels

<!-- .ven lang=en -->
It is given that an interval of nine seconds elapses between a flash and the ensuing thunder. Ascertain the approximate distance of the discharge.

<!-- .vintro -->
**Mova's choice:** option 1 · **The right answer:** option 4 · wrong ✗ · **Who acts:** interval, you · **What happens:** give, elapse, ensue, ascertain · **To what, where:** It, approximate distance

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This is exam question 2 of lesson 18 «Thunder, sirens and how fast sound travels» of the physics 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/physics/18-thunder-sirens-and-how-fast-sound-travels/#e2).

## The question {#question}

<!-- .note -->
*Sentence 1:* It is given that an interval of nine seconds elapses between a flash and the ensuing thunder.

```conllu
# sent_id = question:physics:18-thunder-sirens-and-how-fast-sound-travels:e2:1
# text = It is given that an interval of nine seconds elapses between a flash and the ensuing thunder.
1	It	it	PRON	PRP	Case=Nom|Gender=Neut|Number=Sing|Person=3|PronType=Prs	3	nsubj:pass	_	_
2	is	be	AUX	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	3	aux:pass	_	_
3	given	give	VERB	VBN	Tense=Past|VerbForm=Part|Voice=Pass	0	root	_	_
4	that	that	SCONJ	IN	_	10	mark	_	_
5	an	a	DET	DT	Definite=Ind|PronType=Art	6	det	_	_
6	interval	interval	NOUN	NN	Number=Sing	10	nsubj	_	_
7	of	of	ADP	IN	_	9	case	_	_
8	nine	nine	NUM	CD	NumForm=Word|NumType=Card	9	nummod	_	_
9	seconds	second	NOUN	NNS	Number=Plur	6	nmod	_	_
10	elapses	elapse	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	3	advcl	_	_
11	between	between	ADP	IN	_	13	case	_	_
12	a	a	DET	DT	Definite=Ind|PronType=Art	13	det	_	_
13	flash	flash	NOUN	NN	Number=Sing	10	obl	_	_
14	and	and	CCONJ	CC	_	17	cc	_	_
15	the	the	DET	DT	Definite=Def|PronType=Art	17	det	_	_
16	ensuing	ensue	VERB	VBG	VerbForm=Ger	17	amod	_	_
17	thunder	thunder	NOUN	NN	Number=Sing	13	conj	_	SpaceAfter=No
18	.	.	PUNCT	.	_	3	punct	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **give** | present · passive |  | It |  |  |  |  | vn give-13.1-1 «NP V NP»: subject=Theme |
| 2 | **elapse** | present | a interval of nine seconds |  |  |  |  | between a flash and the ensuing thunder | tree rules |
| 3 | **ensue** | gerund |  |  |  |  |  |  | vn occur-48.3-1 «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.

<!-- .note -->
*Sentence 2:* Ascertain the approximate distance of the discharge.

```conllu
# sent_id = question:physics:18-thunder-sirens-and-how-fast-sound-travels:e2:2
# text = Ascertain the approximate distance of the discharge.
1	Ascertain	ascertain	VERB	VB	Mood=Imp|VerbForm=Fin	0	root	_	_
2	the	the	DET	DT	Definite=Def|PronType=Art	4	det	_	_
3	approximate	approximate	ADJ	JJ	Degree=Pos	4	amod	_	_
4	distance	distance	NOUN	NN	Number=Sing	1	obj	_	_
5	of	of	ADP	IN	_	7	case	_	_
6	the	the	DET	DT	Definite=Def|PronType=Art	7	det	_	_
7	discharge	discharge	NOUN	NN	Number=Sing	4	nmod	_	SpaceAfter=No
8	.	.	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 approximate distance of the discharge |  |  |  |  | vn discover-84 «NP V NP»: agent=Agent distance=Topic |

## The options {#options}

### Option 1 · ← Mova's choice {#o1}

<!-- .ven lang=en -->
Nine kilometres

```conllu
# sent_id = question:physics:18-thunder-sirens-and-how-fast-sound-travels:e2:o1:1
# text = Nine kilometres
1	Nine	nine	NUM	CD	NumForm=Word|NumType=Card	2	nummod	_	_
2	kilometres	kilometre	NOUN	NNS	Number=Plur	0	root	_	_
```

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

### Option 2 {#o2}

<!-- .ven lang=en -->
Twenty-seven kilometres

```conllu
# sent_id = question:physics:18-thunder-sirens-and-how-fast-sound-travels:e2:o2:1
# text = Twenty-seven kilometres
1	Twenty	twenty	NUM	CD	NumForm=Word|NumType=Card	3	compound	_	SpaceAfter=No
2	-	-	PUNCT	HYPH	_	1	punct	_	SpaceAfter=No
3	seven	seven	NUM	CD	NumForm=Word|NumType=Card	4	nummod	_	_
4	kilometres	kilometre	NOUN	NNS	Number=Plur	0	root	_	_
```

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

### Option 3 {#o3}

<!-- .ven lang=en -->
One kilometre

```conllu
# sent_id = question:physics:18-thunder-sirens-and-how-fast-sound-travels:e2:o3:1
# text = One kilometre
1	One	one	NUM	CD	NumForm=Word|NumType=Card	2	nummod	_	_
2	kilometre	kilometre	NOUN	NN	Number=Sing	0	root	_	_
```

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

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

<!-- .ven lang=en -->
Three kilometres

```conllu
# sent_id = question:physics:18-thunder-sirens-and-how-fast-sound-travels:e2:o4:1
# text = Three kilometres
1	Three	three	NUM	CD	NumForm=Word|NumType=Card	2	nummod	_	_
2	kilometres	kilometre	NOUN	NNS	Number=Plur	0	root	_	_
```

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

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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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