2015卫生职称英语考试语法之介词+which（whom）引出的定语从句：

这种定语从句在修饰人时，介词后只用whom，修饰物时只用which，而不用that.例如：

e.g.The man with whom I share the room is a young teacher fresh from college.

与我同屋的人是一位刚从大学毕业的青年教师。

（fresh from school 刚由学校毕业）

e.g.This is the shelf on which I keep my books.这是我放书的架子。

e.g.The famous economist of whom we have often heard will come to give us a lecture next Friday.

我们常听说的那位经济学家下周五将给我们讲课。

（hear of： 听说 ）

（give a lecture： 讲课，讲演 ）

（attend a lecture 听报告；上课）

注：

当介词位于从句句末时，作为介词宾语的which和whom则仍可改用that，也可省略，如上面最后两句可改为；

This is the shelf （which或that）I keep my books on.

The famous economist（whom或that）we have often heard of will come to give us a lecture next Friday.