高教版（2021）基础模块3Unit 7 Natural Disasters精品复习练习题

Unit7 Natural Disasters知识串讲

重点单词

重点短语

重点语法

主语从句和表语从句

主语从句在主句中充当主语，可以分为3类：

1. 由从属连词that、whether、if引导

主语从句在句首时，不能用if，只能用whether。

That she survived the accident is a miracle.

Whether we will hold a party tomorrow depends on the weather.

2. 由连接代词who、whom、whose、which、what、whoever、whatever等引导

Whoever breaks the law should be punished.

3. 由连接副词when、where、why、how引导

Where the test will be given is not yet decided.

为了避免主语部分过于冗长，导致句子头重脚轻，通常使用it作为形式主语，而主语从句放在后面作为真正的主语。

It is certain that she will do well in her exam.

It is common knowledge that the whale is not a fish.

It was reported that the US was under the terrorist attack.

表语从句又叫主语补语从句，在主句中充当表语，位于系动词之后。

与主语从句类似，表语从句也可以用从属连词、连接代词、连接副词引导。

The fact is that we have lost the game.

This is what I want to tell you.

The question is how he did it.

reason作主语或why引导的主语从句作主语时，表语从句用that引导，不用because。

The reason is that he got up late.

Why he is absent is that he got up late.

表语从句that is because...强调原因，that is why...强调结果。

I was angry. That was because he didn’t understand me.

That is why she failed to pass the exam.

That is the reason why she failed to pass the exam.

* 上面的例句为定语从句，注意与表语从句的区别。