---Could you tell me when your father___back?---I’m not sure now. but when he ___next week, I’ll tell you.
--- How many students are there in your school?--- I don’t know, but I’m sure ______ number of the students in my school _____ larger than that in yours.
I like swimming better than climbing, because I think climbing is ________ swimming.
We haven’t got any coffee. Let’s have tea __________.
Don’t say bad words ______ your friends. It’s ________.
____________ careful you are, _____________ mistakes you’ll make.