(1) 从属连词that。 如：That they were in truth sisters was clear from the facialresemblance between them.

很明显，她们确是亲姐妹，她们的脸型很相似。

(2) 从属连词whether。如：

Whether he’ll come here isn’t clear. 他是否会来这里还不清楚。

(3) 连接代词who, whom, whose, what, which, whoever, whatever, whichever

连接副词 where, when, how, why。如：

What she did is not yet known. 她干了什么尚不清楚。

How this happened is not clear to anyone. 这事怎样发生的，谁也不清楚。

Whoever comes is welcome. 不论谁来都欢迎。

Wherever yoare is my home ---- my only home. 你所在的任何地方就是我的家----我唯一的家。