25．How convenient the public transportation is! There ______ be any difficulty traveling around．
| A．mustn't | B．wouldn't | C．shouldn't | D．needn't |
_________ to reach them on the phone, we sent an email instead.
| A．Fail | B．Failed | C．To fail | D．Having failed |
What shall human beings do if oilsometime in the future?
| A．will run out | B．runs out of | C．runs out | D．will be run out |
Chen Chunlong is a hero ofLiaocheng can be proud.
| A．who | B．whom | C．that | D．which |
It was not until mid-night_______ they reached the camp site.
| A．that | B．when | C．while | D．before |
－Why not have a meeting to discuss about it?
－.
| A．It’s hard to answer | B．I don’t know, either |
| C．Because we have no time left | D．That sounds fine to me |