How long do you think it will be _______ scientists succeed in providing a cure for cancer?
| A．when | B．after | C．since | D．before |
—Why are your eyes so red? You ________ have slept well last night.
—Yeah, I stayed up late writing a report.
| A．can't | B．mustn't |
| C．needn't | D．won't |
Harry is feeling uncomfortable.He ________ too much at the party last night.
| A．could drink | B．should drink |
| C．would have drunk | D．must have drunk |
Days later, my brother called to say he was all right, but ________ say where he was.
| A．mustn't | B．shouldn't |
| C．wouldn't | D．mightn't |
The door ________ open, no matter how hard she pushed.
| A．shouldn't | B．couldn't |
| C．wouldn't | D．mightn't |
—Shall I inform him of the change of the schedule right now?
—I am afraid you ________， in case he comes late for the meeting.
| A．will | B．must |
| C．may | D．can |