---
title: Ascertain the principal function of the buttress roots of rainforest… — The Amazon forest floor: leafcutters,… · tree and pragmatics
description: Ascertain the principal function of the buttress roots of rainforest trees. Exam question 4 of lesson 157 «The Amazon forest floor: leafcutters, army ants, tapirs, jaguars and the giant spider» of the biology course of Mova's primary school, with the dependency tree and pragmatics of the question an
---

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# Exam question 4 · The Amazon forest floor: leafcutters, army ants, tapirs, j…

<!-- .ven lang=en -->
Ascertain the principal function of the buttress roots of rainforest trees.

<!-- .vintro -->
**Mova's choice:** option 1 · **The right answer:** option 2 · wrong ✗ · **Who acts:** you · **What happens:** ascertain · **To what, where:** principal function

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This is exam question 4 of lesson 157 «The Amazon forest floor: leafcutters, army ants, tapirs, jaguars and the giant spider» 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/157-the-amazon-forest-floor/#e4).

## The question {#question}

```conllu
# sent_id = question:biology:157-the-amazon-forest-floor:e4:1
# text = Ascertain the principal function of the buttress roots of rainforest trees.
1	Ascertain	ascertain	VERB	VB	Mood=Imp|VerbForm=Fin	0	root	_	_
2	the	the	DET	DT	Definite=Def|PronType=Art	4	det	_	_
3	principal	principal	ADJ	JJ	Degree=Pos	4	amod	_	_
4	function	function	NOUN	NN	Number=Sing	1	obj	_	_
5	of	of	ADP	IN	_	8	case	_	_
6	the	the	DET	DT	Definite=Def|PronType=Art	8	det	_	_
7	buttress	buttress	NOUN	NN	Number=Sing	8	compound	_	_
8	roots	root	NOUN	NNS	Number=Plur	4	nmod	_	_
9	of	of	ADP	IN	_	11	case	_	_
10	rainforest	rainforest	NOUN	NN	Number=Sing	11	compound	_	_
11	trees	tree	NOUN	NNS	Number=Plur	8	nmod	_	SpaceAfter=No
12	.	.	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 principal function of the buttress roots of rainforest trees |  |  |  |  | vn discover-84 «NP V NP»: agent=Agent function=Topic |

<!-- .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 {#o1}

<!-- .ven lang=en -->
They capture fruit falling from the canopy

```conllu
# sent_id = question:biology:157-the-amazon-forest-floor:e4:o1:1
# text = They capture fruit falling from the canopy
1	They	they	PRON	PRP	Case=Nom|Number=Plur|Person=3|PronType=Prs	2	nsubj	_	_
2	capture	capture	VERB	VBP	Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
3	fruit	fruit	NOUN	NN	Number=Sing	2	obj	_	_
4	falling	fall	VERB	VBG	VerbForm=Ger	3	acl	_	_
5	from	from	ADP	IN	_	7	case	_	_
6	the	the	DET	DT	Definite=Def|PronType=Art	7	det	_	_
7	canopy	canopy	NOUN	NN	Number=Sing	4	obl	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **capture** | present | They | fruit |  |  |  |  | vn steal-10.5-1 «NP V NP»: agent=Agent fruit=Theme |
| 2 | **fall** | gerund | fruit *not said here* |  |  | the canopy |  |  | vn escape-51.1-1 «NP V PP.initial\_location»: agent=Theme from canopy=Initial\_Location |

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

<!-- .ven lang=en -->
They support the tall tree in a thin layer of soil by spreading widely

```conllu
# sent_id = question:biology:157-the-amazon-forest-floor:e4:o2:1
# text = They support the tall tree in a thin layer of soil by spreading widely
1	They	they	PRON	PRP	Case=Nom|Number=Plur|Person=3|PronType=Prs	2	nsubj	_	_
2	support	support	VERB	VBP	Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
3	the	the	DET	DT	Definite=Def|PronType=Art	5	det	_	_
4	tall	tall	ADJ	JJ	Degree=Pos	5	amod	_	_
5	tree	tree	NOUN	NN	Number=Sing	2	obj	_	_
6	in	in	ADP	IN	_	9	case	_	_
7	a	a	DET	DT	Definite=Ind|PronType=Art	9	det	_	_
8	thin	thin	ADJ	JJ	Degree=Pos	9	amod	_	_
9	layer	layer	NOUN	NN	Number=Sing	2	obl	_	_
10	of	of	ADP	IN	_	11	case	_	_
11	soil	soil	NOUN	NN	Number=Sing	9	nmod	_	_
12	by	by	SCONJ	IN	_	13	mark	_	_
13	spreading	spread	VERB	VBG	Tense=Pres|VerbForm=Part	2	advcl	_	_
14	widely	widely	ADV	RB	_	13	advmod	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **support** | present | They | the tall tree |  | a thin layer of soil |  |  | vn admire-31.2 «NP V NP»: agent=Experiencer tree=Stimulus |
| 2 | **spread** | gerund | They *not said here* |  |  |  |  | widely *property* | vn appear-48.1.1 «NP V»: agent=Theme |

### Option 3 {#o3}

<!-- .ven lang=en -->
They repel animals that would gnaw the trunk by means of long sharp spines

```conllu
# sent_id = question:biology:157-the-amazon-forest-floor:e4:o3:1
# text = They repel animals that would gnaw the trunk by means of long sharp spines
1	They	they	PRON	PRP	Case=Nom|Number=Plur|Person=3|PronType=Prs	2	nsubj	_	_
2	repel	repel	VERB	VBP	Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin	10	nsubj	_	_
3	animals	animal	NOUN	NNS	Number=Plur	2	obj	_	_
4	that	that	PRON	WDT	PronType=Rel	6	nsubj	_	_
5	would	would	AUX	MD	VerbForm=Fin	6	aux	_	_
6	gnaw	gnaw	VERB	VB	VerbForm=Inf	3	acl:relcl	_	_
7	the	the	DET	DT	Definite=Def|PronType=Art	8	det	_	_
8	trunk	trunk	NOUN	NN	Number=Sing	6	obj	_	_
9	by	by	ADP	IN	_	6	obl	_	_
10	means	mean	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
11	of	of	ADP	IN	_	14	case	_	_
12	long	long	ADJ	JJ	Degree=Pos	14	amod	_	_
13	sharp	sharp	ADJ	JJ	Degree=Pos	14	amod	_	_
14	spines	spine	NOUN	NNS	Number=Plur	10	obl	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **repel** | present | They | animals |  |  |  |  | vn amuse-31.1 «NP V NP»: agent=Stimulus animal=Experiencer |
| 2 | **gnaw** | would | animals | the trunk |  |  |  |  | vn chew-39.2 «NP V NP»: agent=Agent trunk=Patient |
| 3 | **mean** | present |  |  |  |  |  | of long sharp spines | vn intend-61.2-1 «NP V S»: agent=Agent |

### Option 4 {#o4}

<!-- .ven lang=en -->
They store water against prolonged drought

```conllu
# sent_id = question:biology:157-the-amazon-forest-floor:e4:o4:1
# text = They store water against prolonged drought
1	They	they	PRON	PRP	Case=Nom|Number=Plur|Person=3|PronType=Prs	2	nsubj	_	_
2	store	store	VERB	VBP	Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
3	water	water	NOUN	NN	Number=Sing	2	obj	_	_
4	against	against	ADP	IN	_	6	case	_	_
5	prolonged	prolong	VERB	VBN	Tense=Past|VerbForm=Part|Voice=Pass	6	amod	_	_
6	drought	drought	NOUN	NN	Number=Sing	2	obl	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **store** | present | They | water |  | prolonged drought |  |  | vn keep-15.2 «NP V NP PP.location»: agent=Agent water=Theme against drought=Location |
| 2 | **prolong** | participle |  |  |  |  |  |  | vn sustain-55.6 «NP V NP PP.instrument»: agent=Agent |

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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.

<!-- /div -->

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