He made a mistake, but then he corrected the situation _______ it got worse.
| A．until | B．when |
| C．before | D．as |
A recent survey revealed that __________ dogs barking incessantly in the night that we disliked most.
| A．was | B．there be | C．it was | D．there were |
If you __________ succeed, you must study as hard as you can.
| A．are going to | B．are to | C．will | D．should |
—Mike, why didn’t you come yesterday?
—I __________, but I had an unexpected visitor.
| A．had | B．would | C．did | D．was going to |
—What about the books?
—This kind of book __________ well.
| A．sell | B．are sold | C．is sold | D．sells |
Unfortunately, when I dropped in, Mr. Smith __________. So we only had time for a few words.
| A．has just left | B．was just leaving | C．had just left | D．just left |