At first, we didn’t know _______to do.

--- You always spend only a little time on your study. You really _____ me down.--- I’m sorry, Mum. I won’t do that again.

I hear they are going to London, but I don’t know ________ they will stay there.

— Could you give me ______ to eat? I’m so hungry.— Of course. Here are some cakes and fruits.

—______ will you come back from Shanghai?    —In one month.