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
—I can’t give up smoking, doctor.
—For your health, I’m afraid you ________.
A．may B．can
C．have to D．must
We ________ fight against pollution.
A．may B．should
C．mustn’t D．needn’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
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
—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
