what后什么从句？

Question

如题所述

Answer 1

一、what可引导主语从句。what 在从句中可作主语、宾语、表语等，不能省略。如：
What he said at the meeting was very important．他在会上所说的非常重要。（宾语）
What surprised us is that he did it alone．使我们吃惊的是他一个人做了那项工作。（主语）

二、引导宾语从句

what可引导宾语从句。what 在从句中可作主语、宾语、表语等，不能省略。如：
They stopped to see what was happening．他们停下来看发生了什么事情。（主语）
The teacher got angry because of what the boy had done．那个男孩子做的事情让老师很生气。（what在宾语从句中作宾语）
三、引导表语从句

what可引导表语从句，what 在从句中可作主语、宾语、表语等，不能省略。如：
Mary is no longer what she used to be．玛丽不再是从前那样了。（what在表语从句中作表语）
The question is what we should do to prevent him from going．问题是我们怎样做才能阻止他去。（what在表语从句中作动词do的宾语）

四、引导同位语从句
what可引导同位语从句修饰表示抽象概念的名词，对所修饰的名词的具体内容进行详细阐述。这类名词有：fact, idea, news, hope, belief, promise, thought, suggestion, proposal等。that在从句中不作句子成分，但不能省略。what 在从句中可作主语、宾语、表语等，不能省略。如：
I have no idea what we should do next．我不知道我们下一步该做什么。（宾语）

Answer 2

what引导名词性从句，what=that it is...，整个句子是表语从句，因为表语是that引导的句子。主语从句是That it is a struggle for them to get used to senior English study puzzles them.

Answer 3

What puzzles them为名词性从句的主语从句，What puzzles them为主语，that it is a struggle for them to get used to senior English study为表语从句。

Answer 4

what puzzles them是整个句子的主语。（what puzzles them) is (blah blah blah...)
主语从句