---
title: Why does a GPS satellite need such a precise clock? — Satellites and GPS · tree and pragmatics
description: Why does a GPS satellite need such a precise clock? Test 11 · ★★ of lesson 38 «Satellites and GPS» of the technology 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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# Test 11 · ★★ · Satellites and GPS

<!-- .ven lang=en -->
Why does a GPS satellite need such a precise clock?

<!-- .vintro -->
**Mova's choice:** option 4 · **The right answer:** option 2 · wrong ✗ · **Who acts:** GPS satellite · **What happens:** need · **To what, where:** precise clock

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This is test 11 · ★★ of lesson 38 «Satellites and GPS» of the technology 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/technology/38-satellites-and-gps/#t11).

## The question {#question}

```conllu
# sent_id = question:technology:38-satellites-and-gps:t11:1
# text = Why does a GPS satellite need such a precise clock?
1	Why	why	ADV	WRB	PronType=Int	6	advmod	_	_
2	does	do	AUX	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	6	aux	_	_
3	a	a	DET	DT	Definite=Ind|PronType=Art	5	det	_	_
4	GPS	GPS	PROPN	NNP	Number=Sing	5	compound	_	_
5	satellite	satellite	NOUN	NN	Number=Sing	6	nsubj	_	_
6	need	need	VERB	VBP	Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
7	such	such	DET	PDT	PronType=Ind	10	det:predet	_	_
8	a	a	DET	DT	Definite=Ind|PronType=Art	10	det	_	_
9	precise	precise	ADJ	JJ	Degree=Pos	10	amod	_	_
10	clock	clock	NOUN	NN	Number=Sing	6	obj	_	SpaceAfter=No
11	?	?	PUNCT	.	_	6	punct	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **need** | present · do-support | a GPS satellite | such precise clock |  |  |  |  | vn want-32.1-1-1 «NP V NP ADV»: agent=Pivot clock=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 clock powers the satellite

```conllu
# sent_id = question:technology:38-satellites-and-gps:t11:o1:1
# text = The clock powers the satellite
1	The	the	DET	DT	Definite=Def|PronType=Art	2	det	_	_
2	clock	clock	NOUN	NN	Number=Sing	3	nsubj	_	_
3	powers	power	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	satellite	satellite	NOUN	NN	Number=Sing	3	obj	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **power** | present | the clock | the satellite |  |  |  |  | tree rules |

### Option 2 · ✓ the right answer {#o2}

<!-- .ven lang=en -->
The phone works out distance from tiny differences in time

```conllu
# sent_id = question:technology:38-satellites-and-gps:t11:o2:1
# text = The phone works out distance from tiny differences in time
1	The	the	DET	DT	Definite=Def|PronType=Art	2	det	_	_
2	phone	phone	NOUN	NN	Number=Sing	3	nsubj	_	_
3	works	work	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
4	out	out	ADP	RP	_	3	compound:prt	_	_
5	distance	distance	NOUN	NN	Number=Sing	3	obl	_	_
6	from	from	ADP	IN	_	8	case	_	_
7	tiny	tiny	ADJ	JJ	Degree=Pos	8	amod	_	_
8	differences	difference	NOUN	NNS	Number=Plur	5	nmod	_	_
9	in	in	ADP	IN	_	10	case	_	_
10	time	time	NOUN	NN	Number=Sing	3	obl	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **work out** | present | the phone | distance from tiny differences |  |  | time |  | vn discover-84 «NP V how S»: agent=Agent |

### Option 3 {#o3}

<!-- .ven lang=en -->
The astronauts need to know the time

```conllu
# sent_id = question:technology:38-satellites-and-gps:t11:o3:1
# text = The astronauts need to know the time
1	The	the	DET	DT	Definite=Def|PronType=Art	2	det	_	_
2	astronauts	astronaut	NOUN	NNS	Number=Plur	3	nsubj	_	_
3	need	need	VERB	VBP	Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
4	to	to	PART	TO	_	5	mark	_	_
5	know	know	VERB	VB	VerbForm=Inf	3	xcomp	_	_
6	the	the	DET	DT	Definite=Def|PronType=Art	7	det	_	_
7	time	time	NOUN	NN	Number=Sing	5	obj	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **need** | present | the astronauts |  |  |  |  |  | vn want-32.1-1-1 «NP V NP S\_INF»: agent=Pivot clause=Theme |
| 2 | **know** *not said to happen* | to-infinitive | the astronauts *not said here* |  |  |  | time |  | vn comprehend-87.2-1-1-1 «NP V»: agent=Experiencer |

### Option 4 · ← Mova's choice {#o4}

<!-- .ven lang=en -->
The clock keeps the satellite in orbit by ticking at exactly the right speed

```conllu
# sent_id = question:technology:38-satellites-and-gps:t11:o4:1
# text = The clock keeps the satellite in orbit by ticking at exactly the right speed
1	The	the	DET	DT	Definite=Def|PronType=Art	2	det	_	_
2	clock	clock	NOUN	NN	Number=Sing	3	nsubj	_	_
3	keeps	keep	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	satellite	satellite	NOUN	NN	Number=Sing	3	obj	_	_
6	in	in	ADP	IN	_	7	case	_	_
7	orbit	orbit	NOUN	NN	Number=Sing	3	obl	_	_
8	by	by	SCONJ	IN	_	9	mark	_	_
9	ticking	tick	VERB	VBG	Tense=Pres|VerbForm=Part	3	advcl	_	_
10	at	at	ADP	IN	_	14	case	_	_
11	exactly	exactly	ADV	RB	_	14	advmod	_	_
12	the	the	DET	DT	Definite=Def|PronType=Art	14	det	_	_
13	right	right	ADJ	JJ	Degree=Pos	14	amod	_	_
14	speed	speed	NOUN	NN	Number=Sing	9	obl	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **keep** | present | the clock | the satellite |  | orbit |  |  | vn keep-15.2 «NP V NP PP.location»: agent=Agent satellite=Theme in orbit=Location |
| 2 | **tick** | gerund | the clock *not said here* |  |  | the right speed |  |  | vn sound\_emission-43.2 «NP V PP.location»: agent=Theme at speed=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: [Satellites and GPS, test 10](https://md.mova.elamur.ai/free/en/corpora/questions/technology/38-satellites-and-gps/t10/)
- next →: [Satellites and GPS, exam 1](https://md.mova.elamur.ai/free/en/corpora/questions/technology/38-satellites-and-gps/e1/)
- ↑ back to [Satellites and GPS](https://md.mova.elamur.ai/free/en/corpora/questions/technology/38-satellites-and-gps/)