---
title: Why would a desert cactus need to guard itself? — Plants deeper: poisonous and stinging… · tree and pragmatics
description: Why would a desert cactus need to guard itself? Test 9 of lesson 255 «Plants deeper: poisonous and stinging plants and staying safe» of the biology 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 9 · Plants deeper: poisonous and stinging plants and staying s…

<!-- .ven lang=en -->
Why would a desert cactus need to guard itself?

<!-- .vintro -->
**Mova's choice:** option 2 · **The right answer:** option 2 · right ✓ · **Who acts:** desert cactus · **What happens:** need, guard · **To what, where:** cactus

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This is test 9 of lesson 255 «Plants deeper: poisonous and stinging plants and staying safe» of the biology 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/biology/255-plants-deeper-poisonous-and-stinging-plants-and-staying-safe/#t9).

## The question {#question}

```conllu
# sent_id = question:biology:255-plants-deeper-poisonous-and-stinging-plants-and-staying-safe:t9:1
# text = Why would a desert cactus need to guard itself?
1	Why	why	ADV	WRB	PronType=Int	5	advmod	_	_
2	would	would	AUX	MD	VerbForm=Fin	5	aux	_	_
3	a	a	DET	DT	Definite=Ind|PronType=Art	5	det	_	_
4	desert	desert	NOUN	NN	Number=Sing	5	compound	_	_
5	cactus	cactus	NOUN	NN	Number=Sing	6	nsubj	_	_
6	need	need	VERB	VBP	Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
7	to	to	PART	TO	_	8	mark	_	_
8	guard	guard	VERB	VB	VerbForm=Inf	6	advcl	_	_
9	itself	itself	PRON	PRP	Case=Acc|Gender=Neut|Number=Sing|Person=3|PronType=Prs|Reflex=Yes	8	obj	_	SpaceAfter=No
10	?	?	PUNCT	.	_	6	punct	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **need** | present | a desert cactus |  |  |  |  |  | vn want-32.1-1-1 «NP V NP S\_INF»: agent=Pivot |
| 2 | **guard** | to-infinitive | a desert cactus *not said here* | cactus |  |  |  |  | vn defend-72.3 «NP V NP»: agent=Agent itself=Beneficiary |

<!-- .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 -->
Cacti are afraid of the dark and the spines keep them company

```conllu
# sent_id = question:biology:255-plants-deeper-poisonous-and-stinging-plants-and-staying-safe:t9:o1:1
# text = Cacti are afraid of the dark and the spines keep them company
1	Cacti	cactus	NOUN	NNS	Number=Plur	3	nsubj	_	_
2	are	be	AUX	VBP	Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin	3	cop	_	_
3	afraid	afraid	ADJ	JJ	Degree=Pos	0	root	_	_
4	of	of	ADP	IN	_	6	case	_	_
5	the	the	DET	DT	Definite=Def|PronType=Art	6	det	_	_
6	dark	dark	NOUN	NN	Number=Sing	3	obl	_	_
7	and	and	CCONJ	CC	_	10	cc	_	_
8	the	the	DET	DT	Definite=Def|PronType=Art	9	det	_	_
9	spines	spine	NOUN	NNS	Number=Plur	10	nsubj	_	_
10	keep	keep	VERB	VBP	Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin	3	conj	_	_
11	them	they	PRON	PRP	Case=Acc|Number=Plur|Person=3|PronType=Prs	10	obj	_	_
12	company	company	NOUN	NN	Number=Sing	10	obj	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **is** | present | Cacti |  |  |  |  | of the dark; afraid *property* | tree rules |
| 2 | **keep** | present | the spines | Cacti *= cactus* |  |  |  |  | vn sustain-55.6-1 «NP V NP ADJ»: agent=Agent they=Theme company=Attribute |

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

<!-- .ven lang=en -->
Its stored water would tempt thirsty animals

```conllu
# sent_id = question:biology:255-plants-deeper-poisonous-and-stinging-plants-and-staying-safe:t9:o2:1
# text = Its stored water would tempt thirsty animals
1	Its	its	PRON	PRP$	Case=Gen|Gender=Neut|Number=Sing|Person=3|Poss=Yes|PronType=Prs	3	nmod:poss	_	_
2	stored	store	VERB	VBN	Tense=Past|VerbForm=Part|Voice=Pass	3	amod	_	_
3	water	water	NOUN	NN	Number=Sing	5	nsubj	_	_
4	would	would	AUX	MD	VerbForm=Fin	5	aux	_	_
5	tempt	tempt	VERB	VB	VerbForm=Inf	0	root	_	_
6	thirsty	thirsty	ADJ	JJ	Degree=Pos	7	amod	_	_
7	animals	animal	NOUN	NNS	Number=Plur	5	obj	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **store** | participle |  |  |  |  |  |  | vn keep-15.2 «NP V NP»: agent=Agent |
| 2 | **tempt** | would | Its stored water |  | thirsty animals |  |  |  | vn urge-58.1-1 «NP V NP»: agent=Agent animal=Recipient |

### Option 3 {#o3}

<!-- .ven lang=en -->
Desert insects eat only spines

```conllu
# sent_id = question:biology:255-plants-deeper-poisonous-and-stinging-plants-and-staying-safe:t9:o3:1
# text = Desert insects eat only spines
1	Desert	desert	NOUN	NN	Number=Sing	2	compound	_	_
2	insects	insect	NOUN	NNS	Number=Plur	3	nsubj	_	_
3	eat	eat	VERB	VBP	Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
4	only	only	ADV	RB	_	5	advmod	_	_
5	spines	spine	NOUN	NNS	Number=Plur	3	obj	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **eat** | present | Desert insects | spines |  |  |  |  | vn eat-39.1-1 «NP V NP»: agent=Agent spine=Patient |

### Option 4 {#o4}

<!-- .ven lang=en -->
It needs spines to drink the rain

```conllu
# sent_id = question:biology:255-plants-deeper-poisonous-and-stinging-plants-and-staying-safe:t9:o4:1
# text = It needs spines to drink the rain
1	It	it	PRON	PRP	Case=Nom|Gender=Neut|Number=Sing|Person=3|PronType=Prs	2	nsubj	_	_
2	needs	need	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
3	spines	spine	NOUN	NNS	Number=Plur	2	obj	_	_
4	to	to	PART	TO	_	5	mark	_	_
5	drink	drink	VERB	VB	VerbForm=Inf	2	xcomp	_	_
6	the	the	DET	DT	Definite=Def|PronType=Art	7	det	_	_
7	rain	rain	NOUN	NN	Number=Sing	5	obj	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **need** | present | It | spines |  |  |  |  | tree rules |
| 2 | **drink** *not said to happen* | to-infinitive | spines *not said here* | the rain |  |  |  |  | vn eat-39.1-1 «NP V NP»: agent=Agent rain=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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