---
title: Ascertain the reason for which the same hemisphere of the Moon is pe… — Day and night, and the Moon's faces · tree and pragmatics
description: Ascertain the reason for which the same hemisphere of the Moon is perpetually presented to the Earth. Exam question 2 of lesson 39 «Day and night, and the Moon's faces» of the physics 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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# Exam question 2 · Day and night, and the Moon's faces

<!-- .ven lang=en -->
Ascertain the reason for which the same hemisphere of the Moon is perpetually presented to the Earth.

<!-- .vintro -->
**Mova's choice:** option 1 · **The right answer:** option 1 · right ✓ · **Who acts:** you · **What happens:** ascertain, present · **To what, where:** reason, same hemisphere

<!-- .vabout -->
This is exam question 2 of lesson 39 «Day and night, and the Moon's faces» 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/39-day-and-night-and-the-moons-faces/#e2).

## The question {#question}

```conllu
# sent_id = question:physics:39-day-and-night-and-the-moons-faces:e2:1
# text = Ascertain the reason for which the same hemisphere of the Moon is perpetually presented to the Earth.
1	Ascertain	ascertain	VERB	VB	Mood=Imp|VerbForm=Fin	0	root	_	_
2	the	the	DET	DT	Definite=Def|PronType=Art	3	det	_	_
3	reason	reason	NOUN	NN	Number=Sing	1	obj	_	_
4	for	for	ADP	IN	_	5	case	_	_
5	which	which	PRON	WDT	PronType=Rel	14	obl	_	_
6	the	the	DET	DT	Definite=Def|PronType=Art	8	det	_	_
7	same	same	ADJ	JJ	Degree=Pos	8	amod	_	_
8	hemisphere	hemisphere	NOUN	NN	Number=Sing	14	nsubj:pass	_	_
9	of	of	ADP	IN	_	11	case	_	_
10	the	the	DET	DT	Definite=Def|PronType=Art	11	det	_	_
11	Moon	Moon	PROPN	NNP	Number=Sing	8	nmod	_	_
12	is	be	AUX	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	14	aux:pass	_	_
13	perpetually	perpetually	ADV	RB	_	14	advmod	_	_
14	presented	present	VERB	VBN	Tense=Past|VerbForm=Part|Voice=Pass	3	acl:relcl	_	_
15	to	to	ADP	IN	_	17	case	_	_
16	the	the	DET	DT	Definite=Def|PronType=Art	17	det	_	_
17	Earth	Earth	PROPN	NNP	Number=Sing	14	obl	_	SpaceAfter=No
18	.	.	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 reason |  |  |  |  | vn discover-84 «NP V NP»: agent=Agent reason=Topic |
| 2 | **present** | present · passive |  | the same hemisphere of the Moon |  |  |  | for the reason; to the Earth; perpetually *property* | vn fulfilling-13.4.1 «NP V NP PP.recipient»: subject=Theme for which=Recipient |

<!-- .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 · ✓ the right answer {#o1}

<!-- .ven lang=en -->
The Moon rotates once upon its axis in each revolution about the Earth

```conllu
# sent_id = question:physics:39-day-and-night-and-the-moons-faces:e2:o1:1
# text = The Moon rotates once upon its axis in each revolution about the Earth
1	The	the	DET	DT	Definite=Def|PronType=Art	2	det	_	_
2	Moon	Moon	PROPN	NNP	Number=Sing	3	nsubj	_	_
3	rotates	rotate	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
4	once	once	ADV	RB	NumForm=Word|NumType=Mult	3	advmod	_	_
5	upon	upon	ADP	IN	_	7	case	_	_
6	its	its	PRON	PRP$	Case=Gen|Gender=Neut|Number=Sing|Person=3|Poss=Yes|PronType=Prs	7	nmod:poss	_	_
7	axis	axis	NOUN	NN	Number=Sing	3	obl	_	_
8	in	in	ADP	IN	_	10	case	_	_
9	each	each	DET	DT	PronType=Tot	10	det	_	_
10	revolution	revolution	NOUN	NN	Number=Sing	3	obl	_	_
11	about	about	ADP	IN	_	13	case	_	_
12	the	the	DET	DT	Definite=Def|PronType=Art	13	det	_	_
13	Earth	Earth	PROPN	NNP	Number=Sing	10	nmod	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **rotate** | present | the Moon |  |  | each revolution about the Earth |  | upon Moon's axis; once *property* | vn roll-51.3.1 «NP.theme V PP.source PP.trajectory PP.destination»: agent=Theme upon axis=Source in revolution=Trajectory |

### Option 2 {#o2}

<!-- .ven lang=en -->
The opposite hemisphere is permanently unlit

```conllu
# sent_id = question:physics:39-day-and-night-and-the-moons-faces:e2:o2:1
# text = The opposite hemisphere is permanently unlit
1	The	the	DET	DT	Definite=Def|PronType=Art	3	det	_	_
2	opposite	opposite	ADJ	JJ	Degree=Pos	3	amod	_	_
3	hemisphere	hemisphere	NOUN	NN	Number=Sing	6	nsubj	_	_
4	is	be	AUX	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	6	cop	_	_
5	permanently	permanently	ADV	RB	_	6	advmod	_	_
6	unlit	unlit	ADJ	JJ	Degree=Pos	0	root	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **is** | present | the opposite hemisphere |  |  |  |  | permanently, unlit *property* | tree rules |

### Option 3 {#o3}

<!-- .ven lang=en -->
The Moon does not rotate upon its axis at all

```conllu
# sent_id = question:physics:39-day-and-night-and-the-moons-faces:e2:o3:1
# text = The Moon does not rotate upon its axis at all
1	The	the	DET	DT	Definite=Def|PronType=Art	2	det	_	_
2	Moon	Moon	PROPN	NNP	Number=Sing	5	nsubj	_	_
3	does	do	AUX	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	5	aux	_	_
4	not	not	PART	RB	Polarity=Neg	5	advmod	_	_
5	rotate	rotate	VERB	VB	VerbForm=Inf	0	root	_	_
6	upon	upon	ADP	IN	_	8	case	_	_
7	its	its	PRON	PRP$	Case=Gen|Gender=Neut|Number=Sing|Person=3|Poss=Yes|PronType=Prs	8	nmod:poss	_	_
8	axis	axis	NOUN	NN	Number=Sing	5	obl	_	_
9	at	at	ADP	IN	_	10	case	_	_
10	all	all	DET	DT	PronType=Tot	5	obl	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **not** **rotate** | present · do-support | the Moon |  |  | all |  | upon Moon's axis | vn roll-51.3.1 «NP.theme V PP.source PP.trajectory PP.destination»: agent=Theme upon axis=Source at all=Trajectory |

### Option 4 {#o4}

<!-- .ven lang=en -->
The Earth obscures the opposite hemisphere

```conllu
# sent_id = question:physics:39-day-and-night-and-the-moons-faces:e2:o4:1
# text = The Earth obscures the opposite hemisphere
1	The	the	DET	DT	Definite=Def|PronType=Art	2	det	_	_
2	Earth	Earth	PROPN	NNP	Number=Sing	3	nsubj	_	_
3	obscures	obscure	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
4	the	the	DET	DT	Definite=Def|PronType=Art	6	det	_	_
5	opposite	opposite	ADJ	JJ	Degree=Pos	6	amod	_	_
6	hemisphere	hemisphere	NOUN	NN	Number=Sing	3	obj	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **obscure** | present | the Earth | the opposite hemisphere |  |  |  |  | vn remedy-45.7 «NP V NP.patient»: agent=Agent hemisphere=Patient |

<!-- 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 -->

<!-- pn -->
- ← previous: [Day and night, and the Moon's faces, exam 1](https://md.mova.elamur.ai/free/en/corpora/questions/physics/39-day-and-night-and-the-moons-faces/e1/)
- next →: [Day and night, and the Moon's faces, exam 3](https://md.mova.elamur.ai/free/en/corpora/questions/physics/39-day-and-night-and-the-moons-faces/e3/)
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