The young man，who by then _______ admission to university，decided to do some part-time jobs to gain more practical experience．
| A．gained | B．was gaining | C．has gained | D．had gained |
As a soldier , you ____ do as the head tells you .
| A．will | B．shall | C．may | D．ought |
There was plenty of time . She ____ .
| A．needn''t hurry | B．mustn''t hurry | C．needn''t have hurried |
| D．mustn''t have hurried |
Look! Xiao Wang is too sleepy to work . He ____ up watching TV .
| A．mustn''t have stayed | B．shouldn''t have stayed |
| C．mustn''t stay | D．ought not to stay |
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 |