—Let’s go to the concert tonight, Michael!

—Sorry, I _______. I have to help my mother with the housework

A．mustn’t B．may not

C．needn’t D．can’t

If the traffic light is red, you ________ cross the road. It’s very dangerous.

A．don’t B．mustn’t

C．needn’t D．wouldn’t

—I have spent too much time playing computer games these days.

—I think so. You _____ stop, for your study and your health.

A．will B．must C．can D．may

We ________ fight against pollution.

A．may B．should

C．mustn’t D．needn’t

—I can’t give up smoking, doctor.

—For your health, I’m afraid you ________.

A．may B．can

C．have to D．must

He did not regret saying what he did but felt that he it differently.

A．could express B．would express

C．could have expressed D．must have expressed

Mr. White _____ at 8:30 for the meeting, but he didn't show up.

A．should have arrived B．should arrive

C．should have had arrived D．should be arriving

—She looks very happy. She ______ have passed the exam.

—I guess so. It’s not difficult after all.

A．should B．could C．must D．might

—Catherine, I have cleaned the room for you.

—Thanks. You______it. I could manage it myself.

A．needn't do B．needn't have done

C．mustn't do D．shouldn't have done

—It’s the office! So you_____know eating is not allowed here.

—Oh, sorry.

A．must B．will C．may D．need