三、as，which是指代主句内容的非限制性定语从句时，表依据、评论与表事实、状态等没有多大差别，又在主句末时，有时可以通用。

1.He is quite pleased，as /which can be seen from his face.他非常高兴，从他的表情可以看出来。

2.You always work hard，as /which everyone knows.大家都知道，你一向勤奋学习。

但是，上面两句把定语从句置主句句首时，就只能用as。

3.This elephant is like a snake，as anybody can see.像任何人都能看见那样，这头象像条蛇。

4.Bamboo is hollow，which makes it very light.竹子是空的，这就使得它很轻。 在否定意义的非限制性定语从句里，一般用which引导。

5.He came to my birthday party，which I didn't expect at all.我完全没有想到，他来参加我的生日聚会了。

四、who，whom，whose等引导非限制性定语从句时，指代人的普通名词、专有名词等。表示正是或专指先行词等情况。在定语从句中作主语、宾语、定语等。

1.Bob's father，who worked on the project，spent four years in Egypt.鲍勃的父亲从事这项工程，在埃及度过了四年。

2.Dad，this is Zheng Jie，who I knew in Paris.爸，这是郑杰，我在巴黎认识的。 这一句是用主格who代替宾格 whom。

3.His mother，whom he loved dearly， died in 1818.他非常爱戴他的母亲，她死于 1818年。

4.Mr King，whose legs were badly hurt， was quickly taken to hospital.金先生的腿受了重伤，他很快就被送去住院了。

n./pron./num....prep.whom;prep. whom;in whose +n.;the +n.of whom等引导非限制性的定语从句。

5.He spoke of a pen-pal，the name of whom /whose name I've never forgotten.他提到过一个笔友，他的名字我从未忘记。

6.About 2，000people，many of whom were Europeans，worked on the project.大约两千人从事过这项工程，其中很多是欧洲人。

7.In his office there are nine clerks，the youngest of whom is Mr Liu.他办公室有9个职员，其中最年轻的是刘先生。

8.I decided to write about Chaplin，one of whose films I had seen several years before.我决定写有关卓别林的文章，他的一部电影我几年前就看过了。

9.We went to hear this famous singer， about whom we had heard many stories.我们去听这个著名的歌唱家演唱。我们已经听说了有关他的很多故事。 品黄黑MYK

10.Mr Pattis，in whose office Ms King was working，was very surprised when he found out her secret.金女士在帕蒂思办公室工作。他发现她的秘密时感到非常惊奇。

五、when，where引导非限制性定语从句时，作定语从句的状语。when =and then， where =and there。why不引导非限制性定语从句。

1.He was quickly taken to hospital，where a doctor wanted to examine Mr King's legs.金先生很快被送去住院，在那里一个医生要检查他的腿。

2.We will put off the outing until next week，when we won't be so busy.我们把郊游推迟到下个星期，那时我们不会那么忙了。

3.He went to America in 1912，where and when he was noticed by an important film director.他在1912年去了美国，当时他在那里引起了一个重要电影导演的注意。

在prep.where /when非限制性定语从句里，where =there，when =then。

4.His head soon appeared out of the second storey windows，from where he could see nothing but trees.他的头很快从第二层楼的一个窗户伸出来了，从那里他只能看见树木。

5.That was in 1929，since when things have been better.那是在1929年，从那时起情况就已经好转了。

6.I went to bed at ten，before when I was reading for an hour.我10点去睡觉，在那时以前我看了1小时的书。

有时候where /when可以用prep.which替换。

7.The southern states wanted to set up a country of their own，where they would be free to keep black slaves.南方各州要建立一个属于他们自己的国家，在那里他们将自由地保留黑人奴隶。

8.I still remembered January 10，on which /when he came to see me.我仍然记得1月10日，那一天他来看我了。

练习题：用所给的词语填空。少数可以用多次。

A.as B.which C.who D.whom E.whose F.when G.where H.by which time I.from which J.from whom K.north of which L.some of whom M .the biggest of which

1.Dick is going to join in the football game，____was agreed at the meeting.

2.My brother had been an engineer，____ was what he wanted to be.

3.He reached Beijing in 1998，____， some time later，he became a professor.

4. ____is said above，the number of the students in our school has increased.

5.Write a letter to a friend，____has some difficulties with his studies.

6.There are four rooms in the house，____ is a drawing room.

7.We will move into the new house next week，____it will be completed.

8.When lost in work，he often was，____he would forget all about eating and sleeping.

9.He is a model worker，____we can learn a lot.

10.They had to delay the sports meet till next week，____the weather will be fine.

11.The workers，____stayed there for two years，came from Africa.

12.The building over there is a hospital，____ is a small river.

13.We shall have to make a decision about Ms King，____story I've just told you.

14.Mr Liu，____I spoke of just now， would go to Australia.

15.The Nile，____electricity is produced，now runs regularly below the dam.

Keys：1.A/B2.B3.G4.A(As)5.C6.M 7.H 8.A 9.J10.F 11.L 12.K 13.E 14.C /D 15.I

在英语中，为了避免重复，句子中的某些部分经常省略，却给理解增加了困难。在近几年的高考试题中，省略现象也十分常见，其基本要点总结如下：

一、并列句中某些相同成分的省略。

This beeper works well, but that one doesn't (work well).

这个寻呼机工作正常, 但那个就不行。

I study at college and my sister (studies) at high school.

我读大学，我妹妹读高中。

二、在when, while, if, as if, though, until, once, whether, unless等连接的状语从句中, 常省略跟主句相同的主语和be动词。

When (I am) in trouble I always turn to her for help.

当我有困难时总是找她帮助。

The letter is to be left here until (it is) called for. 这封信留在这里待领。

三、有形式主语it的主语从句可省略that。

It is an honor (that) I was invited to your birthday party.

我很荣幸被邀请参加你的生日聚会。

It is the third time (that)I have come to China.这是我第三次来中国。

四、在限制性定语从句中可省略作宾语的关系代词whom, which, that。

That is the naughty boy (whom/that) we talked about last week.

他就是我们上周议论的那个淘气男孩。

Is this the radio (that/which) you bought last Saturday?

这是你上周六买的收音机吗?