Without gravity, we _____ walk on the ground as freely as we do now.
| A．couldn’t | B．mustn’t | C．shan’t | D．needn’t |
Christmas Day is usually celebrated on December 25th_________ the birth of Jesus Christ.
| A．in praise of | B．in honor of | C．in terms of | D．in association with |
The traffic problems we are looking forward to seeing ______ have attracted the government’s attention.
| A．solving | B．solve | C．to solve | D．solved |
––Have you seen your aunt lately?
––Yes, in fact I saw her yesterday. I ______ her for several months.
| A．haven’t seen | B．didn’t see | C．hadn’t seen | D．don’t see |
You have a big mouth, Tom. You ______ have told everybody the secret.
| A．can’t | B．shouldn’t | C．mustn’t | D．mightn’t |
—Ring me at six tomorrow morning, will you?
—Why that early? I ______.
| A．will be sleeping | B．will sleep | C．have slept | D．have been sleeping |