________ you come earlier, you ________ met him. He just left half an hour ago.
| A．Should; would | B． Were; could |
| C．Had; would have | D．Could; would have |
Much to our surprise，the witness’s________of the traffic accident differed from the official version in several aspects.
| A．account | B．opinion |
| C．instruction | D．explanation |
China is developing fast.That’s________I think those of my colleagues who deal with China affairs should visit China.
| A．because | B．why |
| C．when | D．how |
Our bad living habits will destroy the earth.Only by changing________we live can we save the earth.
| A．that | B．what |
| C．how | D．where |
It was only when I reread his poems recently________I began to appreciate their beauty.
| A．until | B．that |
| C．then | D．so |
I got an email from my old friend last Sunday.Until then，we________in touch for nearly 3 years.
| A．didn’t get | B．haven’t got |
| C．hadn’t got | D．don’t get |