Most scientists seem to agree that ________ certain limit should be set on ______
sale of cars to ease air pollution.
| A．a; the | B．/; the | C．the; / | D．the; the |
—Shall I lock the lab now before I go home?
—_____. I’ll check it myself later.
| A．Go ahead | B．No problem | C．All right | D．Don’t bother |
. ----Promise you’ll never wear this kind of dress!
----________. What if I will give a performance?
| A．It’s up to you | B．That reminds me | C．That depends | D．I forget that |
I think you should complain----______, of course, you are happy with the way things are.
| A．if | B．unless | C．as | D．because |
. Only when Tom fully recovered ______ back to work.
| A．did he go | B．he went | C．had he gone | D．he had gone |
. ----Has Tom already finished his new story?
----I have no idea. He ______ it last month.
| A．had written | B．was writing | C．would write | D．wrote |