The police are looking for the witnesses,__________ words will make a difference to the victim.
| A．whose | B．which | C．where | D．when |
When Jack arrived he learned Mary _______ for almost an hour.
| A．had gone | B．had set off | C．had left | D．had been away |
The bikes produced in that factory are of high quality. So they ______ well both at home and abroad.
| A．sell | B．are sold | C．may be sold | D．are to be sold |
It ________ my father half an hour to go to work on foot every day.
| A．took | B．takes | C．taken | D．will take |
His sistersince she left home in 1998.
| A．had not been returned | B．has not returned |
| C．had not returned | D．returned |
－Shall I look after your house while you are away?
－______.
| A．If you like | B．It couldn't be better. | C．Of course you can. | D．It's up to you. |