----What time do you start work?
---- _____________.
| A．It’s none of your business. | B．It varies. |
| C．From 8 a.m. to 4 p.m. | D．It doesn’t make any difference |
— We are sorry we can’t stay with you．
— ________．
| A．No, sorry at all | B．I don’t think so |
| C．Don’t think so | D．That’s all right |
—Why did you cancel your trip to the New York?
—We were just about to leave_______ it started to snow．
| A．when | B．before | C．after | D．since |
Dr．Frank failed many times but he finally _______ to find a successful way to solve the problem．
| A．broke off | B．broke up | C．broke down | D．broke through |
—Are you pleased with what he has done?
—Not a bit ．It couldn’t be ________．
| A．so bad | B．much better |
| C．any worse | D．best |
_____ scores of times , but he still couldn’t understand it ．
| A．Having explained | B．Having been explained |
| C．Though it was explained | D．It was explained |