--Has your teacher returned from America yet?
--Yes, but he _______ here for only three days before his company sent him to Africa．
| A．was | B．has been | C．will be | D．would be |
The streets are all dry . It ____ during the night .
| A．can''t have rained | B．mustn''t have rained |
| C．couldn''t rain | D．shouldn''t have rained |
Water ____ be changed into vapour but it ____ be heated to its boiling point .
| A．may ; can | B．can ; must | C．may ; needn''t | D．must ; may |
____ you like something to drink now ?
| A．Do | B．Will | C．Can | D．Would |
I ____ take a job . No one ____ stop me .
| A．will ; shall | B．will ; may | C．should ; will | D．shall ; may |
“When ____ he leave the hospital ? ”I asked the doctor .
| A．will | B．shall | C．can | D．may |