部门名称大全（1） 由连词that引导的主语从句:引导词that无含义/在句中不做成分/不可以省。
例如：That you will win the medal ems unlikely.
（2） 用连词 whether 引导的主语从句: whether有含义(是否)/在句中不做成分/不可以省。
注意：引导主语从句，不能用if，只能用whether。
例如：Whether we will hold a party in the open air tomorrow depends on the weather.
（3） 用连接代词引导的主语从句
在由连接代词who, who, whom, which, what, whoever, whomever, whichever, whatever引导的名词性从句中，其连接代词在句中起名词性作用，担当一定成分.
例如：What you need is more practice.
whatever, whoever在主语从句中不含疑问中国未来经济意义。它引导威宁地震主语从句，并在从句中作主语、宾语、表语等。
Whoever breaks the law should be punished. （主语从句）
（ ＝Anyone who breaks the law should be punished. ）
（4）用连接副词when, where, why, how引导的名词性从句(其连接副词有含义,在句中作状语。)
例如:Where we should leave it is a problem.
三.注意点: it构成的主语从句
（1）由连词that引导的主语从句，在大多数情况下会放到句子的后面，而用代词it作形式主语。
例如：That light travels in straight lines is known to all.
=It is known to all that light travels in straight lines.
(但当what引导的主语从句表示“…的东西”时，一般不用it作形式主语。)抗病毒药
错:It is a book what he wants.
对:What he wants is a book.
另外，需要注意的是，it作形式主语代替主语从句时，要注意和as引导的定语从句的区别。试比较：
It was reported that the US was under the terrorist attack.
As was reported, the US was under the terrorist attack.
（2）常见用it作形式主语的复合句结构
<a> It is +名词+从句
It is a fact that… 事实是……
It is good news that … ……是好消息
类似的名词还有：a pity；a wonder；a good thing； no wonder； surpri等。
<b> It is +形容词+从句
It is necessary that … 有必要……
It is clear that … 很清楚……
It is likely that … 很可能……
It is important that … 重要的是……
类似的形容词还有：strange; natural; obvious; true; good; wonderful; possible; unlikely; quite;
unusual; certain; evident; worth-while; surprising; interesting; astonishing, etc.
需要注意的是，这类主语从句中，谓语动词很多为“（should）＋动词原形”，即要用虚拟语气。
<c> It is +过去分词+从句
It is said that … 据说……
It is reported that … 据报道……
It has been proved that … 已证明……
It must be proved that… 必须指出……
类似的过去分词还有：known; estimated; expected; believed; thought; hoped; noted; discusd; required;
decided; suggested; demanded; made clear; found out,etc.
四．练习
1. _____ as much as one-fifth of all timber harvested is not ud.
A. The estimate B. The estimated
shutoffC. They are estimated D. It is estimated that
2. _____ some mammals came to live in the a is not known.
A. Which B. Since C. Although D. How 十三岁
3. _____ we have achieved is attributed to the guidance of our parents.
A. Whoever B. Whatever C. However D. That
禁止停车标语
4. _____ wealthy does not necessarily mean that a man is greedy.
A. For the reason that he is B. Just becau he is
C. The reason of being D. That he is
5. Although ___ happened in this developed country sounds like science fiction, it could occur
elwhere in the world.
A. which B. what C. how D. it
6. _____ she had forgotten to take her notebook.
A. That occurred to her B. She occurred that
C. To her that occurred D. It occurred to her that
7. I am sure that _____ she said is wrong.
A. which B. all C. this D. what
8. We lost our way in the forest, and ____ made matters wor was that it was getting dark.
A. that B. which C. it D. what
9. _____ or not is still uncertain.
A. He’s coming B. If he is coming
C. That coming D. Whether he’s coming
10. It’s _____ he’ll be able to come.
A. doubt whether B. doubtful C. doubt it D. doubtful whether
11. ______ he is at work in the heart of the big city or at home in the quiet suburb, Dick’s life is tied to machines.五年级下册数学教案
A. Whether B. Till C. If D. Unless
12. _____ he saw both surprid and frightened him.
A. That B. When C. What D. Which
13. _____ is warm sunshine.
A. What do we all need. B. What all we need
C. What we need D. What we all need
14. _____ is a pity that he should feel so upt.
A. What B. That C. He D. It
15. _____ a spoonful of soil can tell us so much about the structure and early history of the moon.
A. Remarkable B. Quite remarkably
C. It is remarkable that D. It is remarkable fact that
16. _____ you nominate will be elected.
A. Who B. Whom C. Whomever D. That’s
17. _____ book you borrow must be returned within a week.
