适用于：人教课标高一英语下学期必修3 Unit 4 Grammar新授课课件

主语从句
主语从句是在复合句中充当主语的从句, 通常放在主句谓语动词之前或由形式主语it代替, 而本身放在句子末尾。
How the book will sell depends on its author.
That he is the best student in the class is obvious.
引导主语从句的关联词有三类：
1) 从属连词that。如: That they were true sisters was clear from the facial resemblance between them.
很明显, 她们确是亲姐妹, 她们的脸型很相似。
2) 从属连词whether。如：
Whether he’ll come here isn’t clear.  
他是否会来这里还不清楚。
3) 连接代词who, whom, whose, what, which, whoever, whatever, whichever, 连接副词 where, when, how, why。
What she did is not yet known.  
她干了什么尚不清楚。