--- title: Identify the principal reason for which an opaque body casts a shadow. — Light and shadows · tree and pragmatics description: Identify the principal reason for which an opaque body casts a shadow. Exam question 1 of lesson 20 «Light and shadows» of the physics course of Mova's primary school, with the dependency tree and pragmatics of the question and of each option; Mova's choice was wrong. --- [Mova](https://md.mova.elamur.ai/free/en/) · [this page in HTML](https://mova.elamur.ai/free/en/corpora/questions/physics/20-light-and-shadows/e1/) [home](https://md.mova.elamur.ai/free/en/) / [corpora](https://md.mova.elamur.ai/free/en/corpora/) / [questions](https://md.mova.elamur.ai/free/en/corpora/questions/) / [Physics](https://md.mova.elamur.ai/free/en/corpora/questions/physics/) / [Light and shadows](https://md.mova.elamur.ai/free/en/corpora/questions/physics/20-light-and-shadows/) / e1 # Exam question 1 · Light and shadows Identify the principal reason for which an opaque body casts a shadow. **Mova's choice:** option 1 · **The right answer:** option 3 · wrong ✗ · **Who acts:** you, opaque body · **What happens:** identify, cast · **To what, where:** principal reason, shadow This is exam question 1 of lesson 20 «Light and shadows» of the physics 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/physics/20-light-and-shadows/#e1). ## The question {#question} ```conllu # sent_id = question:physics:20-light-and-shadows:e1:1 # text = Identify the principal reason for which an opaque body casts a shadow. 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 10 obl _ _ 7 an a DET DT Definite=Ind|PronType=Art 9 det _ _ 8 opaque opaque ADJ JJ Degree=Pos 9 amod _ _ 9 body body NOUN NN Number=Sing 10 nsubj _ _ 10 casts cast VERB VBZ Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin 4 acl _ _ 11 a a DET DT Definite=Ind|PronType=Art 12 det _ _ 12 shadow shadow NOUN NN Number=Sing 10 obj _ SpaceAfter=No 13 . . PUNCT . _ 1 punct _ _ ``` | # | 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 | **cast** | present | a opaque body | a shadow | | | | for the principal reason | vn build-26.1 «NP V NP PP.beneficiary»: agent=Agent shadow=Product for which=Beneficiary | 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} The body absorbs all heat from its surroundings ```conllu # sent_id = question:physics:20-light-and-shadows:e1:o1:1 # text = The body absorbs all heat from its surroundings 1 The the DET DT Definite=Def|PronType=Art 2 det _ _ 2 body body NOUN NN Number=Sing 3 nsubj _ _ 3 absorbs absorb VERB VBZ Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin 0 root _ _ 4 all all DET DT PronType=Tot 5 det _ _ 5 heat heat NOUN NN Number=Sing 3 obj _ _ 6 from from ADP IN _ 8 case _ _ 7 its its PRON PRP$ Case=Gen|Gender=Neut|Number=Sing|Person=3|Poss=Yes|PronType=Prs 8 nmod:poss _ _ 8 surroundings surroundings NOUN NNS Number=Ptan 3 obl _ _ ``` | # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | 1 | **absorb** | present | the body | all heat | | body's surroundings | | | vn absorb-39.8 «NP V NP PP.source»: agent=Goal heat=Theme from surroundings=Source | ### Option 2 {#o2} Light curves around the body ```conllu # sent_id = question:physics:20-light-and-shadows:e1:o2:1 # text = Light curves around the body 1 Light light NOUN NN Number=Sing 2 nsubj _ _ 2 curves curve VERB VBZ Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin 0 root _ _ 3 around around ADP IN _ 5 case _ _ 4 the the DET DT Definite=Def|PronType=Art 5 det _ _ 5 body body NOUN NN Number=Sing 2 obl _ _ ``` | # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | 1 | **curve** | present | Light | | | the body | | | vn knead-26.5 «NP.material V PP.product»: agent=Material | ### Option 3 · ✓ the right answer {#o3} Light is propagated in straight lines and is obstructed by the body ```conllu # sent_id = question:physics:20-light-and-shadows:e1:o3:1 # text = Light is propagated in straight lines and is obstructed by the body 1 Light light NOUN NN Number=Sing 3 nsubj:pass _ _ 2 is be AUX VBZ Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin 3 aux:pass _ _ 3 propagated propagate VERB VBN Tense=Past|VerbForm=Part|Voice=Pass 0 root _ _ 4 in in ADP IN _ 6 case _ _ 5 straight straight ADJ JJ Degree=Pos 6 amod _ _ 6 lines line NOUN NNS Number=Plur 3 obl _ _ 7 and and CCONJ CC _ 9 cc _ _ 8 is be AUX VBZ Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin 9 aux:pass _ _ 9 obstructed obstruct VERB VBN Tense=Past|VerbForm=Part|Voice=Pass 3 conj _ _ 10 by by ADP IN _ 12 case _ _ 11 the the DET DT Definite=Def|PronType=Art 12 det _ _ 12 body body NOUN NN Number=Sing 9 obl _ _ ``` | # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | 1 | **propagate** | present · passive | | Light | | straight lines | | | vn entity\_specific\_modes\_being-47.2 «NP.location V NP»: subject=Theme | | 2 | **obstruct** | present · passive | the body | | | | | | vn discourage-64.5-1 «NP V S\_ING»: agent=Causer | ### Option 4 {#o4} The body emits darkness in the opposite direction ```conllu # sent_id = question:physics:20-light-and-shadows:e1:o4:1 # text = The body emits darkness in the opposite direction 1 The the DET DT Definite=Def|PronType=Art 2 det _ _ 2 body body NOUN NN Number=Sing 3 nsubj _ _ 3 emits emit VERB VBZ Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin 0 root _ _ 4 darkness darkness NOUN NN Number=Sing 3 obj _ _ 5 in in ADP IN _ 8 case _ _ 6 the the DET DT Definite=Def|PronType=Art 8 det _ _ 7 opposite opposite ADJ JJ Degree=Pos 8 amod _ _ 8 direction direction NOUN NN Number=Sing 3 obl _ _ ``` | # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | 1 | **emit** | present | the body | darkness | | the opposite direction | | | vn substance\_emission-43.4 «NP V NP»: agent=Source darkness=Theme | **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. - ← previous: [Light and shadows, test 10](https://md.mova.elamur.ai/free/en/corpora/questions/physics/20-light-and-shadows/t10/) - next →: [Light and shadows, exam 2](https://md.mova.elamur.ai/free/en/corpora/questions/physics/20-light-and-shadows/e2/) - ↑ back to [Light and shadows](https://md.mova.elamur.ai/free/en/corpora/questions/physics/20-light-and-shadows/)