注意：被修饰的名词前面有最高级的形容词，后面有形容词从句时，关系代词只可以用“that”

He is the best student that I have taught.

他是一个我所教过的最棒的学生。

She is the most beautiful girl that I have ever seen.

她是我曾经见过的最美丽的女孩子。

That is the first thing that I do.

这是我首要做的。

Who is the boy who is talking to Linda?

那个与琳达说话的男孩子是谁