What is the area of a circle whose circumference is 12π?
一、先行词与 who, whom, whose 的关系
当先行词是人时可用到以上的关系代词。若在关系代词前有介词，则必须用 whom：介词 + whom
Lily who likes dancing is an American student. …………… 莉莉是一名喜欢跳舞的美国学生。
The man is a doctor. + I just spoke to the man……………. 那个人是医生。我刚才跟那个人说话了。
The man who I just spoke to is a doctor. …………… 刚才跟我说话的人是一位医生。
The man whom I just spoke to is a doctor.
The man to whom I just spoke is a doctor.
The man that I just spoke to is a doctor.
二、who 与 that 在许多情况下可通用，但下列情况宜用 who
True friends are the ones who never leave your heart.
Anyone who has never made a mistake has never tried anything new.
Those who cannot learn from history are doomed to repeat it.
LiMing is talking to an old man from Europe who is very interesting in Chinese culture.
3. 当定语从句中又套定语从句，其中一个用了that，后面一个用 who
The man that I just spoke to is a doctor who works in No.1 People Hospital.
4. there be 开头的句子
There are many children who are riding horses, playing with monkeys in the zoo.
whose 是代词所有格，可代人也可代物，在定语从句中作定语。 代物时，相当于 of which
Lily is dancing whose dress is very beautiful.
This is an English book. + Its cover is red. …………… 这是一本英语书，它的封面是红色的。
This is an English book whose cover is red. …………… 这是一本封面是红色的英语书。
This is an English book the cover of which is red.
The set or configuration of all points whose coordinates satisfy a single equation or one or more algebraic conditions.