The question is which of us should come first.

问题是我们哪一个应当先到。（which在从句中作主语）

That is what he is worried about.

那正是他所担心的。（what在从句中作宾语）

（4）where,when,why,how引导的表语从句

连接副词when,where,how,why除在句中起连接作用外，还在从句中充当时间、地点、方式、原因状语，本身具有词义。

That's where I can't agree with you.

那就是我不能同意你的地方。

This is why Sara was late for the meeting.

这就是萨拉开会迟到的原因。

This is how they overcame the difficulties.

他们就是这样克服困难的。

My strongest memory is when I attended an American wedding.

我印象最深的是我参加一次美国婚礼的情景。

（5）其他连词as if,because,as,as though引导的表语从句

because引导表语从句通常只用于"This/That/It is/was because..."结构中。as if/as though引导的表语从句常置于连系动词look,seem,sound,be,become等后面，常用虚拟语气，表示不存在的动作或状态。

The elephant feels as if/though he were a wall.

大象摸起来像一堵墙。

It sounds as if/though somebody is knocking at the door.

听起来像有人在敲门。

My anger is because you haven't written to me for a long time.

我生气是因为你很长时间不给我写信。

The important points are as follows.

要点如下。

（6）特别应注意的两点

①通常用that引导表语从句的情况：

A.主语是表示"结果"的名词"the result"时。

The result is that many of them become fat.

结果是他们中许多人发胖了。

B.主语是表示"原因；理由"的名词"the reason"时。

The reason why I didn't attend the conference was that I was too busy.

我未出席会议是因为我太忙了。

C.由why引导的从句作主语时。

Why I decided to put off the football match is that the weather was too bad.

我们决定推迟这场足球赛的原因是天气太糟糕了。

D.固定句型"The truth is that..."中，that不能换作其他词，引导的表语从句说明实际情况，相当于"The fact is that..."，意为"实际是......"。

The truth is that I didn't know about it at all.

实际上我一点也不知道这件事。

②语气：

在表示"意愿、要求、命令、建议"等名词后的表语从句，谓语动词常用"should+动词