This kind of medicine has a bad ________on our brains.
| A．affection | B．affect | C．effect | D．result |
Paper produced every year is ________ the world's production of vehicles.
| A．the three times weight of | B．three times the weight of |
| C．as three times heavy as | D．three times as heavier as |
We have done things we ought not to have done and ______ undone things we ought to have done.
| A．left | B．leave | C．will leave | D．leaving |
— Why weren't you at the meeting?
— I ________ for a long distance call from my sister in America.
| A．was waited | B．was waiting | C．has waited | D．have been waiting |
She will have to find some other work for she can't ________ this loud noise any more.
| A．come up with | B．keep up with | C．grow up with | D．put up with |
The boy said ________ couldn't he work out the problem but his teacher didn't know how to do it.
| A．though | B．never | C．hardly | D．not only |