The workers _____busily when the boss came to look for something she ______in the office.
A had worked, had left B were working ; had left C working ; had left D had worked; left
Shy people often avoid situations _____would force them into close contact with other people．
| A．where | B．which | C．when | D．what |
-----How long do you think it will be _____man can finally solve the problem of cancer?
------Well．it depends．
| A．when | B．until | C．after | D．before |
I listened to a report about the Diaoyu Island Dispute last weekend and that was the first time Iabout the subject．
| A．have heard | B．had heard | C．heard | D．would hear |
--------Is it all right if I smoke here?
------- _______，sir．This is a non-smoking section．
| A．No way | B．Go ahead | C．Better not | D．As you please |
If we sit near ______ front of the bus，we will have ________ better view．
| A．不填；the | B．不填；a | C．the；a | D．the； the |