I can think of many cases _______ students obviously knew a lot of English words and expressions but couldn’t write a good essay.
| A．why | B．which | C．as | D．where |
He turned down the request of his friend because it was________the limit of his power.
| A．beyond | B．over | C．off | D．above |
If you had worked hard, you ______ so anxious now．
| A．are not | B．would not have been |
| C．will not be | D．would not be |
______ I'm willing to help, I do not have much time available．
| A．While | B．When | C．Once | D．Since |
The rise of oil prices made scientists search for new energy resources ______ oil．
| A．replace | B．replacing | C．to replace | D．replaced |
You didn't believe John won the first prize at the speech competition, ______?
| A．did he | B．didn't he | C．did you | D．didn't you |