It was not until the teacher had explained it three times _______ how to work out the problem.
| A．did he understand | B．had he understood |
| C．that he understood | D．that he didn’t understood |
Cars play an important role in modem life, but they also cause many problems like air pollution.
| A．should | B．can | C．must | D．will |
—How long have you been studying in No. 8 Middle School?
—More than two years.
—So it will be less than one year you graduate from it.
| A．when | B．before | C．after | D．since |
— the team finished most of their research work?
—Yes, but the rest rather difficult.
| A．Has, are | B．Has, is | C．Have, are | D．Have, is |
Mum, please let us, Lily and me, go to visit the new provincial museum tomorrow, ?
| A．can you | B．will you | C．shall we | D．may we |
—I regret such a silly mistake in the English exam.
— you keep on trying, I don’t really mind whether you can come out top in your class.
| A．making; So long as | B．to have made; As soon as |
| C．to make; Once | D．having made; The moment |