二、引导词：由that， whether， who， when， where， how， why 等引导。
三、先行词：常为某些抽象名词，如：news， idea， word， fact， hope， doubt， belief， possibility， problem， question， thought， promise， information， message， decision， answer， reply等。
The fact that he is the cleverest in the class is known to all. 他是班上最聪明的，这个事实众所周知。
I am interested in the message that a famous star is coming tonight. 我对今晚一个明星要来的消息很感兴趣。
He got the news from Mary that the sports meeting was put off. 他从玛丽那里得知运动会推迟了。
五、 一些表示建议、命令、要求等的名词后所跟的同位语从句中谓语动词要用虚拟语气，即“should + do”，should可省略。例如：
My suggestion that they （should） start at once was accepted. 我建議他们马上出发，他们同意了。
This is our only request that this （should） be settled as soon as possible. 我们唯一的要求是尽快解决这个问题。
We are glad at the news that he will come. 听到他要来这个消息我们很高兴。（news的内容就是that he will come，故that引导的是同位语从句）
We are glad at the news that he told us. 听到他告诉我们的这个消息我们很高兴。（that从句是限制the news的，即我们高兴只是因为他告诉我们的这个news而不是其他的news，故that从句为定语从句）
what， how， if， whatever 等可引导名词性从句，但不能引导定语从句。
that引导同位语从句时，它不充当句子成分，而引导定语从句时，它作为关系代词，既可以充当定语从句的主语，也可以充当定语从句的宾语。如上例 that he told us中的that就充当told的宾语。
同位语从句所修饰的名词比较有限，通常有hope， wish， idea， news， fact， promise， opinion， suggestion， truth等，而定语从句所修饰的名词则非常广泛。 另外，when和where 引导定语从句时，通常只修饰表示时间和地点的名词，而它们引导同位语从句时却不一定;又如why引导定语从句时，它通常只修饰名词the reason，而它引导同位语从句时则不一定。例如：
I have no idea when they will come. 我不知道他们什么时候来。（同位语从句）I ll never forget the days when I lived there. 我永远不会忘记我住在那儿的日子。（定语从句）
We don t understand the problem why this is the best choice. 我们不明白为什么这是最好的选择。（同位语从句）
This is the reason why he didn t come to the meeting. 这就是他没来开会的原因。（定语从句）
1. The fact_______ she works hard is well known to us all.
A. that B. what C. why D. which
2. The fact_______ he was successful proves his ability.
A. that B. what C. which D. why
3. The news_______ he was kidnapped surprised us greatly.
A. what B. that C. why D. when
4. His suggestion_______ the meeting be delayed was turned down.
A. which B. that C. /_______ D. it
5. I have no idea_______ he will start.
A. when B. that C. what D. /
6. I ve come from the government with a message_______ the meeting won t be held tomorrow.
A. if_______ B. that
C. whether D. which
7. The thought_______ he might fail in the exam worried him.
A. when B. which C. what D. that
8. The order_______ the prisoner be set free arrived too late.
A. which_______ B. whether
C. that_______ D. what
9. The nurses are trying their best to reduce the patient s fear_______ he would die of the disease.
A. that B. as
C. of which D. which
10. He often asked me the question_______ the work was worth doing.
A. whether B. where_______
C. that D. when
11. Information has been put forward_______ more high school graduates will be_______ admitted into universities.
A. while B. that C. when D. as
12. It is said that more high school graduates will be admitted into universities; this is the_______ information_______ has been put forward.
A. what B. that C. when D. as
13. She heard a terrible noise，_______ brought her heart into her mouth.
A. it B. which C. this D. that
14. I can t believe the news_______ he was
A. it B. which C. this D. that
15. The fact_______ he failed in the exam is not the one_______ he told me.
A. which; that_______ B. that; /
C. which; which D. /; that （Key ? p. 37）