---Go now?
--- It's too late; tomorrow will be a _________time for you to visit them.
| A．better | B．good | C．best | D．More |
—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 |
We waited and waited．_________ we had been looking forward to ．
| A．Then came the hour | B．Then did the hour come |
| C．Then the hour came | D．The hour then came |