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: This morning, Joey built a sand castle on the beach, and put a toy  flag in the highest tower, but this afternoon the wind  knocked it down.
 Question: Why does the 'it' refer to the flag?
Because A toy flag would be much lighter and more likely to be blown down than a sand castle.

Sentence: When Tommy dropped his ice cream, Timmy giggled, so father gave him a stern look.
 Question: Why does the 'him' refer to timmy?
Because the stern look would be to the one who giggled at Tommys misfortune.

Sentence: Susan knew that Ann's son had been in a car accident, so she told her about it.
 Question: Why does the 'she' refer to susan?

Because susan said the anne your son accident.