—Hi, Lydia. Are you going to the concert on Friday?
—I’d like to. But there are so many problems_______.
| A．remaining to be settled | B．remained settling |
| C．remaining to settle | D．remained to be settled |
What wonderful world it would be if all countries in the world could live peace with one another．
| A．a; \ | B．the; \ |
| C．a; the | D．the; the |
Ournew machines are much cheaper to run．
| A．effective | B．efficient |
| C．energetic | D．Enthusiastic |
______ today, he would get there by Friday．
| A．Were he to leave | B．If he had left |
| C．Did he to leave | D．Had he left |
—Do you mind if I use your reference book?
—No, ______.
| A．look out | B．forget it |
| C．be my guest | D．take it easy |
I really don’t know______ Mary found her lost necklace that day.
| A．where was it that | B．where it was that |
| C．that where | D．it was that where |