which的意思和用法

1、(用作疑问代词)哪一个,哪一些

Which is my seat?哪个座位是我的?

2、(用做关系代词)那一个,那一些

He also had a gun with which to defend himself.他还有一把自卫用的枪。

3、（用作疑问形容词)哪一个,哪一些

Which university did you go to, Oxford or Cambridge?你上过哪所大学?牛津还是剑桥?

4、(用作关系形容词)这个,这些

The doctor told him to give up smoking, which advice he took.医生叮嘱他戒烟,他接受了这一忠告。