In this task you need to give reasons to justify the pronoun coreference relations. Each of the provided inputs contains a sentence with a target pronoun and a question about how to justify the coreference between a noun phrase and the target pronoun. Good practices involve the discussion about how the descriptions attached to the targeted pronoun relate to the noun phrase candidate in the question. The reasoning could come from one or multiple following knowledge types about commonsense: First: 'Property', the knowledge about property of objects (e.g., ice is cold). Second: 'Object', the knowledge about objects (e.g., cats have ears). Third: 'Eventuality', the knowledge about eventuality (e.g., 'wake up' happens before 'open eyes'). Forth: 'Spatial', the knowledge about spatial position (e.g., object at the back can be blocked). Fifth: 'Quantity', the knowledge about numbers (e.g., 2 is smaller than 10). Sixth: all other knowledge if above ones are not suitable. Write the sentence in natural language.

Sentence: Pete envies Martin although he is very successful.
 Question: Why does the 'he' refer to pete?
Because He envies martin.

Sentence: There is a gap in the wall. You can see the garden behind it .
 Question: Why does the 'it' refer to the wall?
Because there is gap garden behind.

Sentence: I was trying to open the lock with the key, but someone had filled the  keyhole with chewing gum, and I couldn't get it out.
 Question: Why does the 'it' refer to the chewing gum?

Because The key could not be put in the lock so it wouldn't need to come out of it.