A warm thought suddenly came to me____ I might substitute the hero to buy some flowers for his mother’s 60th birthday.
| A．if | B．when |
| C．that | D．which |
—She looks very happy. She ________ have passed the exam.
—I guess so. It's not difficult after all.
| A．should | B．must |
| C．could | D．might |
A survey has shown that 40% of those killed in traffic accidents ________ if they had been wearing seat belts.
| A．should have been saved |
| B．must have been saved |
| C．need have been saved |
| D．could have been saved |
—The research on the new flu virus vaccine is challenging and demanding.Who do you think can do the job?
—________ my students have a try?
| A．May | B．Must |
| C．Will | D．Shall |
—Mum, can I watch the TV program for another twenty minutes?
—Sorry, dear, it's time you ________ to bed.
| A．went | B．go |
| C．will go | D．must go |
________ him not to do so, he wouldn't have made such a serious mistake.
| A．If I persuaded | B．Did I persuade |
| C．Had I persuaded | D．If I should persuade |