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。
词义辨析
that和which都可引导定语从句,但以下情况引导定语从句的关系代词只能用that不能用which。
1、当先行词是all, everything, nothing, anything, little等不定代词,或被first, last, only, few, much, some, any, no等词修饰时,应该用关系代词that,不用which。
2、当先行词为形容词最高级所修饰时,关系代词用that不用which。
3、当并列的两个先行词分别表示人和物时,要用关系代词that而不用which。
4、在强调句型“It is〔was〕...that〔who〕...”中,只能用that,不能用which。