3.作介词宾语的关系代词的选择

当介词前置时，不管在限制性或非限制性定语从句中，都可用whom指人，which指物，这只适用于正式语体。

In the dark street，there wasn't a single person to whom she could turn for help．

在漆黑的大街上，没有一个她可以求助的人。

The gentleman about whom you told me yesterday proved to be a thief．

你昨天给我讲述的那个儒雅的人实际上是一个贼。

She wrote a lot of stories for children，of which this is one example．

她创作了很多儿童故事，这就是其中的一个例子。

He mentioned a book the title of which I can't remember now．

他提到一本书，书名我记不起来了。

A survey was carried out on the death rate of new-born babies in that region，the results of which were surprising．

曾经对那个地区的新生儿死亡率进行过调查，其结果令人吃惊。

在非正式语体的限制性定语从句中，介词通常后置，可用who/that指人，that指物，或者用零关系词。

They are the girls(who/that)I went to school with．

她们是跟我一起上学的女孩子。

Tomorrow I will bring here a magazine(that)you asked for．

明天我会把你要的杂志带来的。

在介词后置情况下如果还用whom/which，那就很不自然。