---
title: Ascertain the principal reason for which rusting, once commenced, pr… — Rust: iron's slow fire · tree and pragmatics
description: Ascertain the principal reason for which rusting, once commenced, proceeds into the depth of the metal. Exam question 4 of lesson 13 «Rust: iron's slow fire» of the chemistry course of Mova's primary school, with the dependency tree and pragmatics of the question and of each option; Mova's choice wa
---

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# Exam question 4 · Rust: iron's slow fire

<!-- .ven lang=en -->
Ascertain the principal reason for which rusting, once commenced, proceeds into the depth of the metal.

<!-- .vintro -->
**Mova's choice:** option 1 · **The right answer:** option 3 · wrong ✗ · **Who acts:** you · **What happens:** ascertain, commence, proceed · **To what, where:** principal reason, depth

<!-- .vabout -->
This is exam question 4 of lesson 13 «Rust: iron's slow fire» 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/13-rust-irons-slow-fire/#e4).

## The question {#question}

```conllu
# sent_id = question:chemistry:13-rust-irons-slow-fire:e4:1
# text = Ascertain the principal reason for which rusting, once commenced, proceeds into the depth of the metal.
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	reason	reason	NOUN	NN	Number=Sing	1	obj	_	_
5	for	for	ADP	IN	_	7	case	_	_
6	which	which	DET	WDT	PronType=Int	7	det	_	_
7	rusting	rusting	NOUN	NN	Number=Sing	4	nmod	_	SpaceAfter=No
8	,	,	PUNCT	,	_	10	punct	_	_
9	once	once	ADV	RB	NumForm=Word|NumType=Mult	10	advmod	_	_
10	commenced	commence	VERB	VBN	Tense=Past|VerbForm=Part|Voice=Pass	1	parataxis	_	SpaceAfter=No
11	,	,	PUNCT	,	_	12	punct	_	_
12	proceeds	proceed	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	1	parataxis	_	_
13	into	into	ADP	IN	_	15	case	_	_
14	the	the	DET	DT	Definite=Def|PronType=Art	15	det	_	_
15	depth	depth	NOUN	NN	Number=Sing	12	obl	_	_
16	of	of	ADP	IN	_	18	case	_	_
17	the	the	DET	DT	Definite=Def|PronType=Art	18	det	_	_
18	metal	metal	NOUN	NN	Number=Sing	15	nmod	_	SpaceAfter=No
19	.	.	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 reason |  |  |  | for which rusting | vn ensure-99 «NP V NP PP.beneficiary»: agent=Precondition reason=Theme for rusting=Beneficiary |
| 2 | **commence** | participle |  |  |  |  |  | once *property* | vn begin-55.1-1-1 «NP.eventuality V»: agent=Eventuality |
| 3 | **proceed** | present |  |  |  | the depth of the metal |  |  | vn begin-55.1 «NP V S\_INF»: 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 {#o1}

<!-- .ven lang=en -->
The rust dissolves the paint on other surfaces

```conllu
# sent_id = question:chemistry:13-rust-irons-slow-fire:e4:o1:1
# text = The rust dissolves the paint on other surfaces
1	The	the	DET	DT	Definite=Def|PronType=Art	2	det	_	_
2	rust	rust	NOUN	NN	Number=Sing	3	nsubj	_	_
3	dissolves	dissolve	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
4	the	the	DET	DT	Definite=Def|PronType=Art	5	det	_	_
5	paint	paint	NOUN	NN	Number=Sing	3	obj	_	_
6	on	on	ADP	IN	_	8	case	_	_
7	other	other	ADJ	JJ	Degree=Pos	8	amod	_	_
8	surfaces	surface	NOUN	NNS	Number=Plur	3	obl	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **dissolve** | present | the rust | the paint |  | other surfaces |  |  | vn break-45.1 «NP V NP»: agent=Agent paint=Patient |

### Option 2 {#o2}

<!-- .ven lang=en -->
The rust attracts magnets that tear the metal

```conllu
# sent_id = question:chemistry:13-rust-irons-slow-fire:e4:o2:1
# text = The rust attracts magnets that tear the metal
1	The	the	DET	DT	Definite=Def|PronType=Art	2	det	_	_
2	rust	rust	NOUN	NN	Number=Sing	3	nsubj	_	_
3	attracts	attract	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
4	magnets	magnet	NOUN	NNS	Number=Plur	3	obj	_	_
5	that	that	PRON	WDT	PronType=Rel	6	nsubj	_	_
6	tear	tear	VERB	VBP	Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin	4	acl:relcl	_	_
7	the	the	DET	DT	Definite=Def|PronType=Art	8	det	_	_
8	metal	metal	NOUN	NN	Number=Sing	6	obj	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **attract** | present | the rust | magnets |  |  |  |  | vn lure-59.3 «NP V NP»: agent=Agent magnet=Patient |
| 2 | **tear** | present | magnets | the metal |  |  |  |  | vn run-51.3.2 «PP.location V NP»: agent=Initial\_Location metal=Theme |

### Option 3 · ✓ the right answer {#o3}

<!-- .ven lang=en -->
The rust flakes away and exposes fresh iron

```conllu
# sent_id = question:chemistry:13-rust-irons-slow-fire:e4:o3:1
# text = The rust flakes away and exposes fresh iron
1	The	the	DET	DT	Definite=Def|PronType=Art	2	det	_	_
2	rust	rust	NOUN	NN	Number=Sing	3	nsubj	_	_
3	flakes	flake	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
4	away	away	ADV	RB	_	3	advmod	_	_
5	and	and	CCONJ	CC	_	6	cc	_	_
6	exposes	expose	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	3	conj	_	_
7	fresh	fresh	ADJ	JJ	Degree=Pos	8	amod	_	_
8	iron	iron	NOUN	NN	Number=Sing	6	obj	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **flake away** | present | the rust |  |  |  |  | away *property* | vn carve-21.2-1 «NP V ADVP-Middle»: agent=Patient |
| 2 | **expose** | present | the rust *not said here* | fresh iron |  |  |  |  | vn indicate-78 «NP V NP»: agent=Pivot iron=Topic |

### Option 4 {#o4}

<!-- .ven lang=en -->
The rust conducts heat into the metal

```conllu
# sent_id = question:chemistry:13-rust-irons-slow-fire:e4:o4:1
# text = The rust conducts heat into the metal
1	The	the	DET	DT	Definite=Def|PronType=Art	2	det	_	_
2	rust	rust	NOUN	NN	Number=Sing	3	nsubj	_	_
3	conducts	conduct	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
4	heat	heat	NOUN	NN	Number=Sing	3	obj	_	_
5	into	into	ADP	IN	_	7	case	_	_
6	the	the	DET	DT	Definite=Def|PronType=Art	7	det	_	_
7	metal	metal	NOUN	NN	Number=Sing	3	obl	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **conduct** | present | the rust | heat |  | the metal |  |  | vn accompany-51.7 «NP V NP PP.destination»: agent=Agent heat=Theme into metal=Destination |

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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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