---
title: Identify the principal reason for which plastic debris persists in t… — Plastics: useful and stubborn · tree and pragmatics
description: Identify the principal reason for which plastic debris persists in the marine environment for prolonged periods. Exam question 2 of lesson 29 «Plastics: useful and stubborn» of the chemistry course of Mova's primary school, with the dependency tree and pragmatics of the question and of each option; 
---

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# Exam question 2 · Plastics: useful and stubborn

<!-- .ven lang=en -->
Identify the principal reason for which plastic debris persists in the marine environment for prolonged periods.

<!-- .vintro -->
**Mova's choice:** option 1 · **The right answer:** option 1 · right ✓ · **Who acts:** you, plastic debris · **What happens:** identify, persist, prolong · **To what, where:** principal reason, marine environment

<!-- .vabout -->
This is exam question 2 of lesson 29 «Plastics: useful and stubborn» of the chemistry 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/chemistry/29-plastics-useful-stubborn/#e2).

## The question {#question}

```conllu
# sent_id = question:chemistry:29-plastics-useful-stubborn:e2:1
# text = Identify the principal reason for which plastic debris persists in the marine environment for prolonged periods.
1	Identify	identify	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	reason	reason	NOUN	NN	Number=Sing	1	obj	_	_
5	for	for	ADP	IN	_	6	case	_	_
6	which	which	PRON	WDT	PronType=Rel	9	obl	_	_
7	plastic	plastic	ADJ	JJ	Degree=Pos	8	amod	_	_
8	debris	debris	NOUN	NN	Number=Sing	9	nsubj	_	_
9	persists	persist	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	4	parataxis	_	_
10	in	in	ADP	IN	_	13	case	_	_
11	the	the	DET	DT	Definite=Def|PronType=Art	13	det	_	_
12	marine	marine	ADJ	JJ	Degree=Pos	13	amod	_	_
13	environment	environment	NOUN	NN	Number=Sing	9	obl	_	_
14	for	for	ADP	IN	_	16	case	_	_
15	prolonged	prolong	VERB	VBN	Tense=Past|VerbForm=Part|Voice=Pass	16	amod	_	_
16	periods	period	NOUN	NNS	Number=Plur	9	obl	_	SpaceAfter=No
17	.	.	PUNCT	.	_	1	punct	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **identify** | imperative | you *not said here* | the principal reason |  |  |  |  | vn characterize-29.2-1-1 «NP V NP S\_ING»: agent=Agent reason=Theme |
| 2 | **persist** | present | plastic debris |  |  | the marine environment |  | for the principal reason; for prolonged periods | vn exist-47.1 «NP V PP.location»: agent=Theme in environment=Location |
| 3 | **prolong** | participle |  |  |  |  |  |  | vn sustain-55.6 «NP V NP PP.instrument»: agent=Agent |

<!-- .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 -->
Few microorganisms are capable of decomposing it

```conllu
# sent_id = question:chemistry:29-plastics-useful-stubborn:e2:o1:1
# text = Few microorganisms are capable of decomposing it
1	Few	few	ADJ	JJ	Degree=Pos	2	amod	_	_
2	microorganisms	microorganism	NOUN	NNS	Number=Plur	4	nsubj	_	_
3	are	be	AUX	VBP	Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin	4	cop	_	_
4	capable	capable	ADJ	JJ	Degree=Pos	0	root	_	_
5	of	of	SCONJ	IN	_	6	mark	_	_
6	decomposing	decompose	VERB	VBG	Tense=Pres|VerbForm=Part	4	advcl	_	_
7	it	it	PRON	PRP	Case=Acc|Gender=Neut|Number=Sing|Person=3|PronType=Prs	6	obj	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **is** | present | Few microorganisms |  |  |  |  | capable *property* | tree rules |
| 2 | **decompose** | gerund | Few microorganisms *not said here* | it |  |  |  |  | tree rules |

### Option 2 {#o2}

<!-- .ven lang=en -->
Salt water converts it into stone

```conllu
# sent_id = question:chemistry:29-plastics-useful-stubborn:e2:o2:1
# text = Salt water converts it into stone
1	Salt	salt	NOUN	NN	Number=Sing	2	compound	_	_
2	water	water	NOUN	NN	Number=Sing	3	nsubj	_	_
3	converts	convert	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
4	it	it	PRON	PRP	Case=Acc|Gender=Neut|Number=Sing|Person=3|PronType=Prs	3	obj	_	_
5	into	into	ADP	IN	_	6	case	_	_
6	stone	stone	NOUN	NN	Number=Sing	3	obl	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **convert** | present | Salt water | it |  |  |  | into stone *result* | vn turn-26.6.1-1 «NP V NP.patient PP.result»: agent=Agent it=Patient into stone=Result |

### Option 3 {#o3}

<!-- .ven lang=en -->
It is replenished continually by marine animals of many kinds

```conllu
# sent_id = question:chemistry:29-plastics-useful-stubborn:e2:o3:1
# text = It is replenished continually by marine animals of many kinds
1	It	it	PRON	PRP	Case=Nom|Gender=Neut|Number=Sing|Person=3|PronType=Prs	3	nsubj:pass	_	_
2	is	be	AUX	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	3	aux:pass	_	_
3	replenished	replenish	VERB	VBN	Tense=Past|VerbForm=Part|Voice=Pass	0	root	_	_
4	continually	continually	ADV	RB	_	3	advmod	_	_
5	by	by	ADP	IN	_	7	case	_	_
6	marine	marine	ADJ	JJ	Degree=Pos	7	amod	_	_
7	animals	animal	NOUN	NNS	Number=Plur	3	obl	_	_
8	of	of	ADP	IN	_	10	case	_	_
9	many	many	ADJ	JJ	Degree=Pos	10	amod	_	_
10	kinds	kind	NOUN	NNS	Number=Plur	7	nmod	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **replenish** | present · passive | marine animals of many kinds | It |  |  |  | continually *property* | vn fill-9.8 «NP V NP.destination»: agent=Agent subject=Destination |

### Option 4 {#o4}

<!-- .ven lang=en -->
It is dissolved and redeposited each night

```conllu
# sent_id = question:chemistry:29-plastics-useful-stubborn:e2:o4:1
# text = It is dissolved and redeposited each night
1	It	it	PRON	PRP	Case=Nom|Gender=Neut|Number=Sing|Person=3|PronType=Prs	3	nsubj	_	_
2	is	be	AUX	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	3	aux:pass	_	_
3	dissolved	dissolve	VERB	VBN	Tense=Past|VerbForm=Part|Voice=Pass	0	root	_	_
4	and	and	CCONJ	CC	_	5	cc	_	_
5	redeposited	redeposit	VERB	VBN	Tense=Past|VerbForm=Part|Voice=Pass	3	conj	_	_
6	each	each	DET	DT	PronType=Tot	7	det	_	_
7	night	night	NOUN	NN	Number=Sing	3	obl:unmarked	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **dissolve** | present · passive |  | It |  |  | night |  | vn break-45.1 «NP V NP»: subject=Patient |
| 2 | **redeposit** | participle |  |  |  |  |  |  | tree rules |

<!-- 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 -->

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