---
title: Hollow tubes are strong and light, which is why bicycle frames and t… — Building strong things: bridges, towers and shapes · tree and pragmatics
description: Hollow tubes are strong and light, which is why bicycle frames and the bones of birds are hollow. Who acts: Hollow tubes, bicycle frames. A sentence of the lesson «Building strong things: bridges, towers and shapes» of the world course of Mova's primary school with its dependency tree and the pragma
---

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# Building strong things: bridges, towers and shapes, sentence 13

<!-- .ven lang=en -->
Hollow tubes are strong and light, which is why bicycle frames and the bones of birds are hollow.

<!-- .vintro -->
**Who acts:** Hollow tubes, bicycle frames · **What happens:** be

<!-- .vabout -->
This is a sentence of the lesson «Building strong things: bridges, towers and shapes» of the world course of Mova's primary school. The page gives its syntax tree — a dependency tree in the style of Universal Dependencies — and its pragmatics clause by clause: who acts (Hollow tubes, bicycle frames), what happens, when and where, as Mova's frames read it from the tree.

## The tree {#tree}

```conllu
# sent_id = school:world:086-building-strong-things.lesson:13
# text = Hollow tubes are strong and light, which is why bicycle frames and the bones of birds are hollow.
# source = school lesson (ours)
# course = world
# lesson = 086-building-strong-things.lesson
# annotation = Mova annot: Rust (en) → Haiku 5.5 (medium, Batches API) patches; gates UD 2.18; agreed by treeagree rules (Stanza, Trankit, spaCy trf): R1-cc-next ×1, R8-pos-agree ×1
1	Hollow	hollow	ADJ	JJ	Degree=Pos	2	amod	_	_
2	tubes	tube	NOUN	NNS	Number=Plur	4	nsubj	_	_
3	are	be	AUX	VBP	Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin	4	cop	_	_
4	strong	strong	ADJ	JJ	Degree=Pos	0	root	_	_
5	and	and	CCONJ	CC	_	6	cc	_	_
6	light	light	ADJ	JJ	Degree=Pos	4	conj	_	Agree=R8-pos-agree|Haiku=4:conj|HaikuPos=NOUN:NN:Number=Sing
7	,	,	PUNCT	,	_	4	punct	_	_
8	which	which	PRON	WDT	PronType=Rel	9	nsubj	_	_
9	is	be	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	6	acl:relcl	_	_
10	why	why	ADV	WRB	PronType=Int	9	advmod	_	_
11	bicycle	bicycle	NOUN	NN	Number=Sing	12	compound	_	_
12	frames	frame	NOUN	NNS	Number=Plur	19	nsubj	_	_
13	and	and	CCONJ	CC	_	15	cc	_	Agree=R1-cc-next|Haiku=12:cc
14	the	the	DET	DT	Definite=Def|PronType=Art	15	det	_	_
15	bones	bone	NOUN	NNS	Number=Plur	12	conj	_	_
16	of	of	ADP	IN	_	17	case	_	_
17	birds	bird	NOUN	NNS	Number=Plur	15	nmod	_	_
18	are	be	AUX	VBP	Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin	19	cop	_	_
19	hollow	hollow	ADJ	JJ	Degree=Pos	9	ccomp	_	_
20	.	.	PUNCT	.	_	4	punct	_	_
```

## Pragmatics {#pragmatics}

<!-- .note -->
No stored speech act for this sentence.

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **is** | present | Hollow tubes |  |  |  |  | strong *property* | tree rules |
| 2 | **be** |  | Hollow tubes *not said here* |  |  |  |  |  | tree rules |
| 3 | **be** | present |  |  |  |  |  |  | vn exist-47.1 «NP V»: agent=Theme |
| 4 | **is** | present | bicycle frames and the bones of birds |  |  |  |  | hollow *property* | tree rules |

<!-- .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.

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**Licence: [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0/)**, as the whole of Mova corpus 0.4, of which this treebank (the agreed school, `mova-school-agreed-en.conllu`) is part. The lessons were written for Mova's primary school. Sentence `school:world:086-building-strong-things.lesson:13`.

**The tree:** Mova annot: Rust (en) → Haiku 5.5 (medium, Batches API) patches; gates UD 2.18; agreed by treeagree rules (Stanza, Trankit, spaCy trf): R1-cc-next ×1, R8-pos-agree ×1. **The frames** are read from the tree by Mova's frames reader (`prag`) when this page is built, the lesson read in order, so a pronoun may be resolved from an earlier sentence.

See the [release 0.4](https://md.mova.elamur.ai/free/en/releases/0.4/).

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