Mrs. White became a teacher in 1985. She _____ for twenty years by next summer.
| A．will teach | B．would have taught | C．has been teaching | D．will have been teaching |
Had they known what was coming next, they ________ second thoughts.
| A．may have | B．could have |
| C．must have had | D．might have had |
Grace doesn't want to move to New York because she thinks if she ________ there, she wouldn't be able to see her parents very often.
| A．lives | B．would live |
| C．has lived | D．were to live |
If he had spent more time practising speaking English before, he ________ able to speak it much better now.
| A．will be | B．would be |
| C．has been | D．would have been |
If we ________ a table earlier, we wouldn't be standing here in a queue.
| A．have booked | B．booked |
| C．book | D．had booked |
—Where ________ Mary have put the empty bottles?
—She ________ them away. They must be somewhere.
| A．can; can't have thrown |
| B．must; needn't |
| C．must; must have thrown |
| D．can; mustn't have thrown |