---
title: Eratosthenes saw no shadow at noon in one city but a shadow at anoth… — How we know: measuring the sky · tree and pragmatics
description: Eratosthenes saw no shadow at noon in one city but a shadow at another the same day. Why? Test 10 · ★★★ of lesson 28 «How we know: measuring the sky» of the space course of Mova's primary school, with the dependency tree and pragmatics of the question and of each option; Mova's choice was right.
---

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# Test 10 · ★★★ · How we know: measuring the sky

<!-- .ven lang=en -->
Eratosthenes saw no shadow at noon in one city but a shadow at another the same day. Why?

<!-- .vintro -->
**Mova's choice:** option 2 · **The right answer:** option 2 · right ✓ · **Who acts:** Eratosthenes · **What happens:** see · **To what, where:** shadow, one city

<!-- .vabout -->
This is test 10 · ★★★ of lesson 28 «How we know: measuring the sky» of the space 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/space/28-how-we-know-measuring-the-sky/#t10).

## The question {#question}

<!-- .note -->
*Sentence 1:* Eratosthenes saw no shadow at noon in one city but a shadow at another the same day.

```conllu
# sent_id = question:space:28-how-we-know-measuring-the-sky:t10:1
# text = Eratosthenes saw no shadow at noon in one city but a shadow at another the same day.
1	Eratosthenes	Eratosthenes	PROPN	NNP	Number=Sing	2	nsubj	_	_
2	saw	see	VERB	VBD	Mood=Ind|Number=Sing|Person=3|Tense=Past|VerbForm=Fin	0	root	_	_
3	no	no	DET	DT	PronType=Neg	4	det	_	_
4	shadow	shadow	NOUN	NN	Number=Sing	2	obj	_	_
5	at	at	ADP	IN	_	6	case	_	_
6	noon	noon	NOUN	NN	Number=Sing	2	obl	_	_
7	in	in	ADP	IN	_	9	case	_	_
8	one	one	NUM	CD	NumForm=Word|NumType=Card	9	nummod	_	_
9	city	city	NOUN	NN	Number=Sing	2	obl	_	_
10	but	but	CCONJ	CC	_	12	cc	_	_
11	a	a	DET	DT	Definite=Ind|PronType=Art	12	det	_	_
12	shadow	shadow	NOUN	NN	Number=Sing	9	conj	_	_
13	at	at	ADP	IN	_	17	case	_	_
14	another	another	DET	DT	PronType=Ind	17	det	_	_
15	the	the	DET	DT	Definite=Def|PronType=Art	17	det	_	_
16	same	same	ADJ	JJ	Degree=Pos	17	amod	_	_
17	day	day	NOUN	NN	Number=Sing	2	obl	_	SpaceAfter=No
18	.	.	PUNCT	.	_	2	punct	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **see** | past | Eratosthenes | no shadow |  | one city but a shadow | day; noon |  | vn comprehend-87.2-1-1 «NP V NP»: agent=Experiencer shadow=Stimulus |

<!-- .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:* Why?

```conllu
# sent_id = question:space:28-how-we-know-measuring-the-sky:t10:2
# text = Why?
1	Why	why	ADV	WRB	PronType=Int	0	root	_	SpaceAfter=No
2	?	?	PUNCT	.	_	1	punct	_	_
```

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

## The options {#options}

### Option 1 {#o1}

<!-- .ven lang=en -->
The other city was much nearer the Moon, which blocked the sunlight

```conllu
# sent_id = question:space:28-how-we-know-measuring-the-sky:t10:o1:1
# text = The other city was much nearer the Moon, which blocked the sunlight
1	The	the	DET	DT	Definite=Def|PronType=Art	3	det	_	_
2	other	other	ADJ	JJ	Degree=Pos	3	amod	_	_
3	city	city	NOUN	NN	Number=Sing	6	nsubj	_	_
4	was	be	AUX	VBD	Mood=Ind|Number=Sing|Person=3|Tense=Past|VerbForm=Fin	6	cop	_	_
5	much	much	ADV	RB	_	6	advmod	_	_
6	nearer	near	ADJ	JJR	Degree=Cmp	0	root	_	_
7	the	the	DET	DT	Definite=Def|PronType=Art	8	det	_	_
8	Moon	Moon	PROPN	NNP	Number=Sing	6	obj	_	SpaceAfter=No
9	,	,	PUNCT	,	_	11	punct	_	_
10	which	which	PRON	WDT	PronType=Rel	11	nsubj	_	_
11	blocked	block	VERB	VBD	Mood=Ind|Number=Sing|Person=3|Tense=Past|VerbForm=Fin	6	conj	_	_
12	the	the	DET	DT	Definite=Def|PronType=Art	13	det	_	_
13	sunlight	sunlight	NOUN	NN	Number=Sing	11	obj	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **is** | past | the other city |  |  |  |  | near *property* | tree rules |
| 2 | **block** | past |  | the sunlight |  |  |  |  | vn forbid-64.4-1 «NP V NP»: agent=Causer sunlight=Theme |

### Option 2 · ← Mova's choice · ✓ the right answer {#o2}

<!-- .ven lang=en -->
Earth's surface is curved, so the Sun hits at different angles

```conllu
# sent_id = question:space:28-how-we-know-measuring-the-sky:t10:o2:1
# text = Earth's surface is curved, so the Sun hits at different angles
1	Earth	Earth	PROPN	NNP	Number=Sing	3	nmod:poss	_	SpaceAfter=No
2	's	's	PART	POS	_	1	case	_	_
3	surface	surface	NOUN	NN	Number=Sing	5	nsubj:pass	_	_
4	is	be	AUX	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	5	aux:pass	_	_
5	curved	curve	VERB	VBN	Tense=Past|VerbForm=Part|Voice=Pass	0	root	_	SpaceAfter=No
6	,	,	PUNCT	,	_	10	punct	_	_
7	so	so	ADV	RB	_	10	advmod	_	_
8	the	the	DET	DT	Definite=Def|PronType=Art	9	det	_	_
9	Sun	Sun	PROPN	NNP	Number=Sing	10	nsubj	_	_
10	hits	hit	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	5	advcl	_	_
11	at	at	ADP	IN	_	13	case	_	_
12	different	different	ADJ	JJ	Degree=Pos	13	amod	_	_
13	angles	angle	NOUN	NNS	Number=Plur	10	obl	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **curve** | present · passive |  | Earth's surface |  |  |  |  | vn knead-26.5 «NP V NP.material»: subject=Material |
| 2 | **hit** | present | the Sun |  |  |  |  | at different angles | vn hit-18.1-1 «NP V PP»: agent=Agent at angle=Patient |

### Option 3 {#o3}

<!-- .ven lang=en -->
The Sun was in two places at once

```conllu
# sent_id = question:space:28-how-we-know-measuring-the-sky:t10:o3:1
# text = The Sun was in two places at once
1	The	the	DET	DT	Definite=Def|PronType=Art	2	det	_	_
2	Sun	Sun	PROPN	NNP	Number=Sing	6	nsubj	_	_
3	was	be	AUX	VBD	Mood=Ind|Number=Sing|Person=3|Tense=Past|VerbForm=Fin	6	cop	_	_
4	in	in	ADP	IN	_	6	case	_	_
5	two	two	NUM	CD	NumForm=Word|NumType=Card	6	nummod	_	_
6	places	place	NOUN	NNS	Number=Plur	0	root	_	_
7	at	at	ADP	IN	_	8	case	_	_
8	once	once	ADV	RB	NumForm=Word|NumType=Mult	6	nmod	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **is** | past | the Sun |  |  | two places |  |  | tree rules |

### Option 4 {#o4}

<!-- .ven lang=en -->
One city had taller buildings

```conllu
# sent_id = question:space:28-how-we-know-measuring-the-sky:t10:o4:1
# text = One city had taller buildings
1	One	one	NUM	CD	NumForm=Word|NumType=Card	2	nummod	_	_
2	city	city	NOUN	NN	Number=Sing	3	nsubj	_	_
3	had	have	VERB	VBD	Mood=Ind|Number=Sing|Person=3|Tense=Past|VerbForm=Fin	0	root	_	_
4	taller	tall	ADJ	JJR	Degree=Cmp	5	amod	_	_
5	buildings	building	NOUN	NNS	Number=Plur	3	obj	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **have** | past | One city | taller buildings |  |  |  |  | vn birth-28.2-1 «NP V NP»: agent=Agent building=Patient |

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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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