✔ 最佳答案
a. 'who'; is used to refer to persons by stating what the person(s) does / do.
eg: The man who robbed you was arrested by the police yesterday.
b. 'whom9; is used to refer to persons through another action done by a different subject.
(When the relative pronouns are the object (receiving the action) of the dependent clause, use 'whom9;)
eg: The student whom the teacher had praised finally won the competition.
eg: The most popular karaoke song request is "The girl ..... I marry".
We can use whom to refer to girl as this is the object of the relative clause.
see more:
http://grammar.uoregon.edu/pronouns/relative.html
c. 'which' , is used to refered to a place, thing or idea
eg: The church which had been deserted for many years was demolished last year.
d. that, actually we can u 'that' in all situation
(That" can replace "which", "whom" and "who")
e. 'whose' it means "...'s", "her/his"
(whose" is used to refer to persons through their possessions.)
eg: The family whose house is located on top of the hill is very wealthy.