【名师点拨】

　主语从句主要有三类：

1．由连词引导（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。

That she survived the accident is a miracle.她在事故中幸免于难简直是奇迹。

（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。

例如：Whether she is coming or not doesn't matter too much.她来不来都无关紧要。

2.用连接代词引导的主语从句(在由连接代词who, whose, 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.你所需要的是更多的训练。

3.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： When they will come hasn't been made pubic.

他们什么时候来还不知道。

　温馨提示

1.it 做形式主语,而将主语从句放在句末（尤其是当谓语较短时）。

例如：That light travels in straight lines is known to all.

光沿直线传播，这是众所周知的事。

=It is known to all that light travels in straight lines.

众所周知光沿直线传播。

2.只用whether不用if引导主语从句.

　考点：考查名词性从句

5. It is confirmed that a person can not be actually pleased if ___ he appreciates doing is

ignored by the company as of no value.

A. when B. that C. what D. where

【答案】C

【解析】

试题分析：考查主语从句引导词。句意：如果一个人所喜欢做的事情被公司认为是毫无价值的，确定他不会感到满意的。题干中if从句中包含的he appreciates doing主语从句，从句中缺少doing的宾语，故可