核心问题
What you need most is a good rest.
我知道充当主语的动词不定式和 that 从句都可以用 it(形式主语)来代替,从而被置于句末,例如:
To find a job in these days is difficult. It is difficult to find a job in these days. (AEG) 但不知上面充当主语的 what 从句能否像动词不定式和 that 从句那样也用 it 代替, 从而退居句末?
词典解答
这样的用法并不罕见(参见 it ... what)。下面是一个我们从语法书上查到的例句：
It is a complete mystery what has happened to him. (AEG) 他究竟发生了什么事, 这完全是一件很神秘的事。
练习题
请做下面的英语试题：
—He looks unhappy. —Yes, but he can't say what it is ____ is bothering him. A. as B. what C. why D. where