定语从句 (2)

1、一、as引导的定语从句1. as引导限制性定语从句 在限制性定语从句中，as多和such或the same连用，构成suchas和the sameas结构，能够代替先行词是人或物的名词，例如: I have got into the same trouble as he has. 我遇到了和他一样的麻烦。 Such people as were recommended by him were reliable. 他所推荐的人是可靠的。 Ive never seen such a talented young man as he is. 我从未见过像他这样才华横溢的年轻人。注意:the same

2、 as与the same that的区别比较:This is the same book as I read last week. 这和我上周读的那本书是一样的。 This is the same book that I read last week. 这就是我上周读的那本书。2. 引导非限制性定语从句在非限制性定语从句中，as作为关系代词代替整个句子。As引导的从句位置较灵活，能够位于主句前面、中间后者后面，一般用逗号和主句隔开，通常意为“正如一样，像一样”。As he realized, I was very useful to him. (在前)Air, as we know, is a

3、 gas. (在中)He was a foreigner, as I know from his accent. (在后)3. as引导非限制性定语从句与which引导非限制性定语从句的区别 (1) 位置上的区别: which引导的非限制定语从句指代整个句子时只能放在主句后面，而as引导的从句位置相对较灵活，可在前，可在中，也可在后。As might be expected, John was admitted to the university. 约翰被大学录取了，这时能够预料到的。（as代替后面的句子，在从句中作主语，不能用which代替）Taiwan is, as you know, a

4、n inseparable part of China. 你们知道，台湾是中国不可分割的一部分。（as代替主句:Taiwan is an inseparable part of China，在从句中作宾语，不能用which代替）More American troops are being sent to the Middle East, as/which I have learnt from the newspaper. 更多的美国部队被派往中东地区，这是我从报纸上获悉的。as或which在句尾引导非限制性定语从句，as或which代替整个句子时，通常能够互换，但用which较多，常意为“这个

5、点，这件事”注意:1）非限制性定语从句在句尾时（或句中），关系代词如果不是代替整个句子，而是指代主句中的某个部分时，用which，而不用as，如:Great Salt Lake is fed by freshwater streams, which is about four to five times as salty as the ocean. 大盐湖由淡水河汇集而成，其盐度是大海的四到五倍。（which指代的是主句的主语:Great Salt Lake，而不是指代整个主句，所以不能用as）The current, which is very rapid, makes the river

6、dangerous. 湍急的水流使得这条河流很危险。（which指代的是主句的主语:The current，而不是整个句子，从句尽管在句子中间，但不能用as）2）非限制性定语从句在句尾，且关系代词指代整个句子，当主句和从句在内容上不一致时，即从句的内容对主句的内容起反对、否定等作用时，多用which，如:She married again, which was unexpected. 她又结婚了，这真出乎人们的预料。The young man cheated his friend of much money, which was disgraceful. 这个年轻人骗了他朋友许多钱，真是可耻。

7、3）当引导非限制性定语从句的关系代词前有介词时，只能用which，如:There is a great deal of oxygen around us, without which we could not live. 我们周围有许多氧气，没有它我们就无法生存。4) 非限制性定语从句在句尾时，若关系代词指代整个句子，且意为“正如那样、由可知”时，用as较多，而这些从句几乎成为固定说法。如：Things will turn out contrary to ones wishes, as is often the case. 事与愿违，这是常用的事。（as指代前面整个句子的内容，在从句中作主语）

8、as作关系代词时引导的一些常见结构：as is well known/ as is known to all 总所周知as is often the case 情况常常如此as may be imagined 可以想象as often happens 这种情况常常发生as have been said before 如前所述as is usual with sb 某人经常如此as is natural 很自然as is supposed/ expected/ anticipated 恰如所料as will be shown in 将在中指出5）as引导非限制性定语从句在从句中作主语时，从句的谓

9、语动词通常是be动词，或者是其他系动词，如seem, become等，通常不用行为动词作其谓语，但which引导的非限制性定语从句作主语时，则可用各类动词作从句的谓语，如：He didnt say anything at the meeting, as seemed strange. 会上他一言不发，这很奇怪。She failed in the exam, which surprised all of us. 她考试没及格，这让我们大跌眼镜。（关系代词在从句中作主语，且谓语动词surprise是行为动词，故不能用as）。(2) as后面出现“be+过去分词结构”时，be可以省略，但是在whic

10、h引导的非限制性定语从句中如含有“be+过去分词结构”，be不能省略。He is a teacher, as clear from his manner. 正如他的行为表现出来的那样，他是一名教师。（不能用which，因为这里省略了is）3. 主句是否定句时，as引导的非限制性定语从句位置的不同，会影响句意的不同，如： As has been said above, grammar is not a set of dead rules. 正如前面所说，语法不是一套死条文。 Spiders are not insects, as many people think. =Spiders are n

11、ot insects. But many people think they are. 蜘蛛并不像很多人认为的那样是一种昆虫。 The facts of science are not, as some think, dry and lifeless. 科学并不像有些人想的那样枯燥无味和没有生命力。翻译 Greenland was not a continent, as people thought. 4. as在句首引导非限制性定语从句时，跟其他句型的区别： 1) _ is known to us all, the whale is not a fish but a mammal. 2) _

12、 is known to us all that the whale is not fish but a mammal. 3) _ is known to us all is that the whale is not fish but a mammal.随堂练习2013·天津卷 We have launched another manmade satellite，_ is announced in today's newspaper.A. that B. which C. who D. what 2013·安徽卷 Mo Yan was awarded the No

13、bel Prize for Literature in 2012, _ made one of the Chinese people's longheld dreams come true.A. it B. that C. what D. which 2013·江苏 The president of the World Bank says he has a passion for China，_ he remembers starting as early as his childhood. A. where B. which C. what D. when2013·

14、;辽宁卷 He may win the competition, _ he is likely to get into the national team. A. in which case B. in that case C. in what case D. in whose case2012北京卷 When deeply absorbed in work, _ he often was，he would forget all about eating or sleeping. A. that B. which C. where D. when 2012陕西卷 It is the third

15、 time that she has won the race, _ has surprised us all. A. that B. whereC.whichD. what2011北京卷） Mary was much kinder to Jack than she was to the others, _, of course, make all the others upset. A. whoB. whichC. whatD. that【2011全国卷II）7】Ted came for the weekend wearing only some shorts and a T-shirt,

16、_ is a stupid thing to do in such weather. A. this B. that C. what D. which10四川After graduating from college, I took some time off to go travelling, turned out to be a wise decision. A. that B. which C. when D. where09全国My friend showed me round the town, was very kind of him. A. which B. that C. wh

17、ere D. it 09辽宁Theyve won their last three matches. _I find a bit surprising A. that B. when C. what D. which 09山东Whenever I met her, _ was fairly often, she greeted me with a sweet smile. A. who B. which C. when D. that 08全国The road conditions there turned out to be very good, _was more than we coul

18、d expect. A.it B. what C. which D. that07湖南By serving others, a person focuses on someone other than himself or herself, can be very eye-opening and rewarding. A. who B. which C. what D. that07上海His movie won several awards at the film festival, was beyond his wildest dream. A. whichB. that C. where

19、 D. it05浙江Jim passed the driving test, surprised everybody in the office. A. which B. that C. this D. it04天津Helen was much kinder to her youngest son than to the others, _, of course, made the others envy him.   A. who   B. that   C. what  D. which    2013·山东卷 There is no simple answer, _ is often the case in science. A. as B. that C. when D. where 2013·陕西卷 is often