This is a paraphrasing task. In this task, you're given a sentence and your task is to generate another sentence which express same meaning as the input using different words.
--------
Question: perhaps they could tell us , but they have not chosen to do so .

Answer: they might have told us , but they chose not to say .

Question: not for a second did i see that moving van .

Answer: i did n't see the one truck for a second .

Question: '' did you learn why she mousetrapped us ? ''

Answer:
'' why would she catch us ? ''