---What do you think is the matter with your car? ---Well, it _____ start at all. I mean I turned the key and nothing happened. 

You           be hungry after the long walk．Help yourself to some cakes．

--“Where is Tom?”--“He hasn’t come to school today, I think he ______be ill.”

— Can I pay the bill by check? — Sorry, sir. But it's the management rules of our hotel that payment ______be made in cash.

—Can we run across the road now?—No, we _     . We have to wait until the light turns green.