—Must I return the book tomorrow?—No, you ________.You can keep it for three days.

--The man in a black suit _______ be our youth worker.--- I’m sure it _______ be him. I saw him in the laboratory building some minutes ago.

(2013·高考天津卷)No one ________be more generous; he has a heart of gold.

—Must I buy lunch at school?—No, you needn’t. You __________ bring your own lunch if you want to.

— Mum, would you please buy me an MP5 player? — If you can help do the dishes the whole vacation, you ______ have one as a reward.