1.书中：由连接代词what，whatever，whoever等引导的主语从句一般不可以用it做形式主语。
What he found surprised me. 能否改成 It surprised me what hefound？为何？
2.The government had promised to do_____ lies in its power to ease thehardships of the victims in the flood-stricken area.
A.however B.whichever C.whatever D.wherever
lies in its power 如何翻译呢？为何不选B呢？
3.He's ____ as a “bellyacher”---he's always complaining aboutsomething.
A.who is known C.what is known
who可以引导表语从句，并可作主语，为何不选A呢？
1 书上说的不够了解。当what，whatever，whoever引导名词性关系分句作主语时，因为这种分句本质上是一个名词词组被一个限制性定语修饰，等于一个名词词组，而名词词组作主语，一般是不可以外置的。所以名词性关系分句作主语一般是不可以使用外置主语结构（即不可以用IT作形式主语）。What he found surprised me. = The thing which he found surprised me. 这个句子不可以改为外置主语结构。
2 whichever和whatever之间有什么区别其实就是which和what有什么区别，前者指特定选项内的任何一个或一些，后者则没特定选项。你的句子中并没特定选项，所以用whatever。lies in its power 指在其权限范围内。
3 bellyacher为俚语，指爱发牢骚的人。主语是爱发牢骚的人，这个表语是归属性表语，而不是确认性表语，所以，句子等于He is the kind of person that is known as bellyacher. that定语从句的先行词不是person，而是kind。He is 后接的表语是那种人、那类人，而不是那个人，所以名词性关系分句中隐含的先行词不是人，而是人的品质、素质。所以不需要whoever，而用whatever引导名词性关系分句。
