非限制性定语从句定义：1.非限制性定语从句只是对主句内容，或是先行词的补充，解释或是附加说明。
主句与先行词或是从句之间一般用_____ 分开，常常单独翻译。
没有它，主句意思仍然完整。
2.引导非限制性定语从句的关系代词有as, __________, who, whom, whose等，作定语从句的主语，宾语，表语及定语。
关系副词有__________, ________。
[练习]用下列引导词填空（which, when, who, where, as）：1.The book, __________ he lost yesterday, has been found.2.My brother, __________ lives in New York, has six children.3.__________ you know, I don’t like drinking or smoking.4.We’ll finish this term in July, __________ we will be free.st Sunday they reached Nanjing, __________ a meeting was to be held.[小结] ，That和_______不可引导非限制性定语从句。
(2) 定语从句的省略This is the book __________ he lost yesterday.（这就是他昨天丢的那本书。
）这是一个（限制性/非限制性）定语从句，先行词__________在定语从句中作__________，引导词可以是__________，__________，或是可以__________。
【小结】⑴在限制性定语从句中，当关系代词在从句中作_____语时，关系代词可以省略。
⑵定语从句可简化为分词短语，主动用现在分词，被动过去分词。
（3）考点⑴which 与as 引导定于从句都可以指代整个一句话。
区别:①位置as引导从句位置比较灵活可前，中，后；而which只能放在_____面②意思as正如...，正像...; which这一点,这件事③搭配前面有the same , such，as时，引导定语从句的关系代词用as，不用which。
Air, ______ we know, is a gas.He changed his mind, ________(and this, and that)made me very angry.I have never heard such stories ________ he tells.⑵some/many/(a) few/(a) little/ both/none/ two(基数词) of which /whomI read some books, three of ______ are yellow with years.There are forty students in our classes,most of _______ are from the south.A.asB.whichC.whoD.that（3）定语从句的转化①.He is a good boy with whom you can work. →He is a good boy _____with.A.to workB.workingC.worked②.The train that leaves from Luonan goes to Xi’an.→The train ______ from Luonan goes toXi’an.A.to leaveB.leavingC.left③.The house which was damaged in the fire will be rebuilt soon. →The house _____ in the fire will be rebuilt soon.A.to damageB.damagingC.damaged【注意1】观察下面两句话有什么区别，并翻译He asked me a question which was about my study at school.______________________________。
（如果去掉后面的定语从句，句子的意思完整清楚吗？）This is my motorbike, which was sent to me by my uncle.______________________________。
（去掉后面的定语从句对句子的意思有影响？）(2) 定语从句的省略This is the book __________ he lost yesterday.（这就是他昨天丢的那本书。
）这是一个（限制性/非限制性）定语从句，先行词__________在定语从句中作__________，引导词可以是__________，__________，或是可以__________。
专项练习1.After living in Paris for fifty years he returned to the small town __________ he grew up as a c hild.A.whichB.thatC.whereD.when2.Carol said the work would be done by October, __________ personally I doubt very much.A.itB.thatC.whenD.which3.Dorothy was always speaking highly of her role in the play, __________, of course, made the ot hers unhappy.A.whoB.whichC.thisD.what4.__________ is known to everybody, the moon travels round the earth once every month.A.ItB.AsC.ThatD.What5.The film brought the hours back to me __________ I was taken good care of in that far-away vi llage.A.untilB.thatC.whenD.where6.__________ is mentioned above, the number of the students in senior school is increasing.A.WhichB.AsC.ThatD.It7.In the office I never seem to have time until after 5:30 p.m., __________ many people have got home.A.whose timeB.thatC.on whichD.by which8.All of the flowers now raised here have developed from those __________ in the forest.A.once they grewB.they grew onceC.they once grewD.once grew9.He made another wonderful discovery, __________ of great importance to science.A.which I think isB.which I think it isC.which I think itD.I think is10.He was very rude to the Customs officer, __________ of course made things even worse.A.whoB.whomC.whatD.which11.Recently I bought an ancient Chinese vase, __________ was very reasonable.A.which priceB.the price of whichC.its priceD.the price of whose12.He’s got himself into a dan gerous situation __________ he is likely to lose control over the pla ne.A.whereB.whichC.whileD.why13.I can think of many cases __________ students obviously knew a lot of English words and expr essions but couldn’t write a good essay.A.whyB.whichC.asD.where14.The gentleman ________ you told me yesterday proved to be a thief. A.who B.about whomC.whomD.with whom15.It was an exciting moment for these football fans this year, __________ for the first time in ye ars their team won the World Cup.A.thatB.whileC.whichD.when16.The result of the experiment was very good, __________ we hadn’t expect.A.whenB.thatC.whichD.what17.Have you seen the film Titanic, __________ leading actor is world famous?A.itsB.it’sC.whoseD.which18.John said he’d been working in the office for an hour, __________ was true.A.heB.thisC.whichD.who19.Is this the reason __________ at the meeting for his carelessness in his work?A.he explainedB.what he explainedC.how he explainedD.why he explained20.The famous basketballer, __________ tried to make a comeback, attracted a lot of attention.A.whereB.whenC.whichD.who21.We are living in an age _______ many things are done on computer.A.whichB.thatC.whoseD.when22.We will be shown around the city: schools, museums, and some other places, __________ other visitors seldom go.A.whatB.whichC.whereD.when23.York, __________ last year, is a nice old city.A.that I visitedB.which I visitedC.where I visitedD.in which I visited24.Luckily, we'd brought a road map without __________ we would have lost our way.A.itB. thatC.thisD.which25.The journey around the world took the old sailor nine months, __________ the sailing time was 226 days.A.of whichB.during whichC.from whichD.for which26.The factory produces half a million pairs of shoes every year, 80% __________are sold abroad.A.of whichB.which ofC.of themD.of that27.There are two buildings, __________stands nearly a hundred feet high. (2004湖北卷)A.the largerB.the larger of themC.the larger one thatD.the larger of which28.The English play __________ my students acted at the New Year’s party was a great success.A.for whichB.at whichC.in whichD.on which。