It was not until dark ______ he found that it was the correct way to solve the problem.
| A．that | B．what | C．which | D．when |
（2012江西卷）You can borrow my car you promise not to drive too fast.
| A．unless | B．even if | C．in case | D．as lone as |
It is hard for the Greek government to get over the present difficulties_________ gets more financial support from the European Union.
| A．if | B．unless | C．because | D．since |
He smiled politely ______ Mary apologized for her drunken friends.
| A．as | B．if | C．unless | D．though |
A number of high buildings have arisen _______ there was nothing a year ago but ruins.
| A．when | B．where |
| C．before | D．until |
（2012重庆卷）—Coach, can I continue with the training?
—Sorry, you can’t ______you haven’t recovered from the knee injury.
| A．until | B．before | C．to consider | D．unless |