下列各句中加线的成语，使用恰当的一项是（ ）

This is _____banana ,and that is _____apple.

I missed the beginning of I am a singer yesterday evening.一 ! But you can watch the re-play tonight.

She _____ the children round him and askedthem to listen to her attentively.

We need to get to the root of the problem ________ we can solve it.