---
title: Ascertain the reason for which the Rio Negro and the Solimões flow a… — The Amazon river: pink dolphins, flood… · tree and pragmatics
description: Ascertain the reason for which the Rio Negro and the Solimões flow alongside one another for several kilometres prior to mixing. Exam question 4 of lesson 155 «The Amazon river: pink dolphins, flooded forest, giant fish and piranhas» of the biology course of Mova's primary school, with the dependenc
---

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# Exam question 4 · The Amazon river: pink dolphins, flooded forest, giant fis…

<!-- .ven lang=en -->
Ascertain the reason for which the Rio Negro and the Solimões flow alongside one another for several kilometres prior to mixing.

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

<!-- .vabout -->
This is exam question 4 of lesson 155 «The Amazon river: pink dolphins, flooded forest, giant fish and piranhas» of the biology 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/biology/155-the-amazon-river/#e4).

## The question {#question}

```conllu
# sent_id = question:biology:155-the-amazon-river:e4:1
# text = Ascertain the reason for which the Rio Negro and the Solimões flow alongside one another for several kilometres prior to mixing.
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	12	obl	_	_
6	the	the	DET	DT	Definite=Def|PronType=Art	8	det	_	_
7	Rio	Rio	PROPN	NNP	Number=Sing	8	compound	_	_
8	Negro	Negro	PROPN	NNP	Number=Sing	12	nsubj	_	_
9	and	and	CCONJ	CC	_	11	cc	_	_
10	the	the	DET	DT	Definite=Def|PronType=Art	11	det	_	_
11	Solimões	Solimõe	PROPN	NNPS	Number=Plur	8	conj	_	_
12	flow	flow	VERB	VBP	Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin	3	acl:relcl	_	_
13	alongside	alongside	ADP	IN	_	15	case	_	_
14	one	one	NUM	CD	NumForm=Word|NumType=Card	15	nummod	_	_
15	another	another	DET	DT	PronType=Ind	12	obl	_	_
16	for	for	ADP	IN	_	18	case	_	_
17	several	several	ADJ	JJ	Degree=Pos	18	amod	_	_
18	kilometres	kilometre	NOUN	NNS	Number=Plur	12	obl	_	_
19	prior	prior	ADJ	JJ	Degree=Pos|ExtPos=ADP	21	case	_	_
20	to	to	ADP	IN	_	19	fixed	_	_
21	mixing	mixing	NOUN	NN	Number=Sing	12	obl	_	SpaceAfter=No
22	.	.	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 | **flow** | present | the Rio Negro and the Solimões |  |  | another |  | for the reason; for several kilometres; prior mixing | vn appear-48.1.1 «NP V PP.location»: agent=Theme alongside another=Location |

<!-- .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 two waters differ in temperature, velocity and dissolved substances

```conllu
# sent_id = question:biology:155-the-amazon-river:e4:o1:1
# text = The two waters differ in temperature, velocity and dissolved substances
1	The	the	DET	DT	Definite=Def|PronType=Art	3	det	_	_
2	two	two	NUM	CD	NumForm=Word|NumType=Card	3	nummod	_	_
3	waters	water	NOUN	NNS	Number=Plur	4	nsubj	_	_
4	differ	differ	VERB	VBP	Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
5	in	in	ADP	IN	_	6	case	_	_
6	temperature	temperature	NOUN	NN	Number=Sing	4	obl	_	SpaceAfter=No
7	,	,	PUNCT	,	_	8	punct	_	_
8	velocity	velocity	NOUN	NN	Number=Sing	6	conj	_	_
9	and	and	CCONJ	CC	_	11	cc	_	_
10	dissolved	dissolve	VERB	VBN	Tense=Past|VerbForm=Part|Voice=Pass	11	amod	_	_
11	substances	substance	NOUN	NNS	Number=Plur	6	conj	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **differ** | present | the two waters |  |  | temperature and velocity and dissolved substances |  |  | vn correspond-36.1 «NP V»: agent=Agent |
| 2 | **dissolve** | participle |  |  |  |  |  |  | vn break-45.1 «NP.patient V»: agent=Patient |

### Option 2 {#o2}

<!-- .ven lang=en -->
The fish of each river prevent intermingling

```conllu
# sent_id = question:biology:155-the-amazon-river:e4:o2:1
# text = The fish of each river prevent intermingling
1	The	the	DET	DT	Definite=Def|PronType=Art	2	det	_	_
2	fish	fish	NOUN	NN	Number=Sing	6	nsubj	_	_
3	of	of	ADP	IN	_	5	case	_	_
4	each	each	DET	DT	PronType=Tot	5	det	_	_
5	river	river	NOUN	NN	Number=Sing	2	nmod	_	_
6	prevent	prevent	VERB	VBP	Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
7	intermingling	intermingle	VERB	VBG	VerbForm=Ger	6	xcomp	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **prevent** | present | the fish of each river |  |  |  |  |  | vn forbid-64.4-1 «NP V S\_ING»: agent=Causer clause=Eventuality |
| 2 | **intermingle** | gerund | the fish of each river *not said here* |  |  |  |  |  | vn amalgamate-22.2-1-1 «NP V»: agent=Patient |

### Option 3 {#o3}

<!-- .ven lang=en -->
The one river flows in the contrary direction to the other, so that they cannot join

<!-- fold The tree, 17 words -->
```conllu
# sent_id = question:biology:155-the-amazon-river:e4:o3:1
# text = The one river flows in the contrary direction to the other, so that they cannot join
1	The	the	DET	DT	Definite=Def|PronType=Art	3	det	_	_
2	one	one	NOUN	NN	Number=Sing	3	compound	_	_
3	river	river	NOUN	NN	Number=Sing	4	nsubj	_	_
4	flows	flow	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
5	in	in	ADP	IN	_	8	case	_	_
6	the	the	DET	DT	Definite=Def|PronType=Art	8	det	_	_
7	contrary	contrary	ADJ	JJ	Degree=Pos	8	amod	_	_
8	direction	direction	NOUN	NN	Number=Sing	4	obl	_	_
9	to	to	ADP	IN	_	11	case	_	_
10	the	the	DET	DT	Definite=Def|PronType=Art	11	det	_	_
11	other	other	ADJ	JJ	Degree=Pos	8	nmod	_	SpaceAfter=No
12	,	,	PUNCT	,	_	18	punct	_	_
13	so	so	SCONJ	IN	ExtPos=SCONJ	18	mark	_	_
14	that	that	SCONJ	IN	_	13	fixed	_	_
15	they	they	PRON	PRP	Case=Nom|Number=Plur|Person=3|PronType=Prs	18	nsubj	_	_
16	can	can	AUX	MD	VerbForm=Fin	18	aux	_	SpaceAfter=No
17	not	not	PART	RB	Polarity=Neg	18	advmod	_	_
18	join	join	VERB	VB	VerbForm=Inf	4	conj	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **flow** | present | the one river |  |  | the contrary direction to the other |  |  | vn appear-48.1.1 «NP V PP.location»: agent=Theme in direction=Location |
| 2 | **not** **join** | can | they |  |  |  |  |  | vn mix-22.1-2-1 «NP V»: agent=Patient |

### Option 4 {#o4}

<!-- .ven lang=en -->
A submerged wall separates the two channels

```conllu
# sent_id = question:biology:155-the-amazon-river:e4:o4:1
# text = A submerged wall separates the two channels
1	A	a	DET	DT	Definite=Ind|PronType=Art	3	det	_	_
2	submerged	submerge	VERB	VBN	Tense=Past|VerbForm=Part|Voice=Pass	3	amod	_	_
3	wall	wall	NOUN	NN	Number=Sing	4	nsubj	_	_
4	separates	separate	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
5	the	the	DET	DT	Definite=Def|PronType=Art	7	det	_	_
6	two	two	NUM	CD	NumForm=Word|NumType=Card	7	nummod	_	_
7	channels	channel	NOUN	NNS	Number=Plur	4	obj	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **submerge** | participle |  |  |  |  |  |  | vn other\_cos-45.4 «NP.patient V»: agent=Patient |
| 2 | **separate** | present | a submerged wall | the two channels |  |  |  |  | vn separate-23.1-1-1 «NP V NP»: agent=Agent channel=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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