What did the teacher say just now—Sorry, I didn’t catch it. I _________ something else.

If someone has toan action or policy, they are responsible for it, and may be required to explain it to other people or be punished if it fails．

How many times have you ________ to Shanghai

boy was sittingat the desk, ______ hard when his mother got home.

I think it’s impossible for us to work out the plan in just two days. It’s too difficult.—-You’re right. We can’t be _______ careful and hard while working on it.