A good rest between classes ________ recover brain power to its best and make us perform better in class later.

— _______ we clean the classroom at once?  — No, you _______. You _______ clean it after school. 

John, look at the time._____ you play the piano at such a late hour?

—May I swim here?  — No, you _______.  It is dangerous.

— Could I have a word with you, mum? — Oh, dear, if you ______.