3.虚拟语气强化练习
1. If it hadn't been for your help，we would have been （be） in real trouble.
解析：与过去事实相反的虚拟语气的主句
2. He would have given you more help，if he had not been （not be） so busy.
解析：与过去事实相反的虚拟语气的从句
3. It is high time that we took （take） firm measures to protect our environment.
解析：It is high time +过去式的虚拟形式
4. It was imperative that students finish （finish） their papers before July 1st.
解析：It was imperative that+动词原形的虚拟形式
5. They demanded that the right to vote be given （give） to every adult person.
解析：demand所接宾语从句用动词原形的虚拟形式
6. There was a mistake on my paycheck. I should have received （receive） $10 more.
解析：与过去事实相反的虚拟语气的主句，表示“本应该收到”而实际上没有。
7. I would rather he bought （ buy） the house next year.
解析：would rather后接宾语从句，从句用过去式表示虚拟语气。
8. The manager told us to be friendly to the visitors as if we had met （meet）them before.
解析：as if 所引导的从句用过去完成式表示虚拟语气。
9. Should she come tomorrow，I _________ take her to the museum. × 正确答案为C
[A] can
[B] will
[C] would
[D] must
解析：与将来事实相反的虚拟语气的主句。
10. If we _________ everything ready by now，we should be having a terrible time tomorrow. 正确答案为A
[A] hadn't got
[B] didn't get
[C] wouldn't have got
[D] wouldn't get
解析：从句与现在事实相反，但本身已经是现在完成时（从by now可以看出），所以变为过
去完成时。
4.定语从句和名词性从句强化练习
1. Studies have shown _________ teenagers often suffer from depression. 正确答案为A
解析：that 引导宾语从句
[A] that
[B] which
[C] in which
[D] in that
2. It is a well-known fact _________ a person will move in a circle when he cannot use his eyes to control his direction. 正确答案为A
[A] that
[B] if
[C] when
[D] whether
解析：that 引导同位语从句
3. On the other hand concern is also growing about the possibility of a new economic order_________ resource-rich nations of the Third World would combine to set high commodity prices. 正确答案为C
[A] which
[B] what
[C] that
[D] in that
解析：that 引导同位语从句
4. It is not yet known _________ computers will one day have vision as good as human vision.
正确答案为A
[A] whether
[B] if
[C] that
[D] how
解析：it为形式主语，whether引导真正的主语从句
5. Such attitudes amount to a belief _________ leisure can and should be put to good use. 正确答案为D
[A] which
[B] if
[C] whether
[D] that
解析：that 引导同位语从句
6. The reason for making a decision is _________ a problem exists，goals are wrong，or something is standing in the way of accomplishing them. 正确答案为D
[A] why
[B] because
[C] where
[D] that
解析：that 引导表语从句