This toy Mickey Mouse _______be Amy's. she's the only kid at the picnic.

 —Look! A book is on the floor. Whose is it?—It ______be Rick's. It has his name on it.

 —________ I swim here?—I’m sorry. Children _______ swim alone here.

Food safety is important. Rules        to stop people from food pollution.

The magazine        be Lily’s, for we can find her name on the cover.

The pollution problem here seems to get more and more serious .Something ____with it .

— There is somebody at the door. ________ it be Tom?— No, it _______ be him. It’s just six o’clock. It’s too early.

--______ we clean the classroom at once? --No, you _____. You____ clean it after school.

- You’d better           because you have to drive back home. - OK.

 - Must I clean the Lable now? - No, you ____.  You may do it later.

—______ I take the magazine away from the reading room?— No, you mustn’t. You ______ read it only here.

---Must we donate our pocket money to the poor right now?---No, you _______. You can think it over and do it before Friday.

—Look! The boy in the white shirt ___be Tom. --It ____be him. I saw him enter the library just now. 

—The pollution problem here seems to get more and more serious.--Yes. Something_____about it.

It is usually warm in my hometown in March, but it ____be rather cold sometimes.

— Could I borrow your dictionary?— Of course you ______. 

This book _____ Lucy’s. Look! Her name is on the book. 

— Must I finish the exercise at school? — No, you don’t have to. You          do it at home.

 The boss has given everyone a special holiday, so they      go to work tomorrow .

 —______ you please tell me something about the life in Canada? — Sorry, I______ . I don’t know either. I’m from Australia.