人教版英语必修三第四单元上篇.ppt

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1、UnitUnit4 4 Astronomy:the Astronomy:the science of the starsscience of the starsHow life began on the earth?a cloud of dust1.“Bigbang”2.a violent solid globeproduce gases3.atmospere4.water appeared5.plants appeared6.animals appearedproduce oxygen1.They were in time to produce carbon,nitrogen,water v

2、apour and other gases,which were to make the earths atmosphere.最终产生了碳、氮气、水蒸气和其他多种气体，从而形成了地球的大气层。(1)in time 最终，迟早=finally/eventually 例:If you keep on,youll succeed in time.及时 We were just in time for the bus.Word and Phrase on time 准时例：Can we arrive in Beijing on time or not?in no time 立刻例：Well do up

3、 your car in no time at all.at no time 决不=never例：(辽宁卷)At no time did they actually break the rules of the game.It was unfair to punish them.ahead of time 提前all the time 一直at any time 在任何时候at a time 一次，每次It one time 曾经，同时at the same time 同时from time to time 时不时地，偶尔take one s time从容不迫，不着急 to doas time

4、 goes on 随着时间的推移 2.What many scientists believe is that the continued presence of water allowed the earth to dissolve harmful gases and acids into the oceans and seas.This produced a chain reaction,which made it possible for life to develop.很多科学家相信，由于地球上长期有水存在，它使得地球把有害很多科学家相信，由于地球上长期有水存在，它使得地球把有害气体和

5、酸性物质溶解在海洋里。气体和酸性物质溶解在海洋里。这就产生了连锁反应这就产生了连锁反应,使得生命有可能开始发展了使得生命有可能开始发展了。(1)主语从句，表语从句主语从句，表语从句例例1(陕西省陕西省)The manager wants to see changes in the company,and I am sure he will .A.in particularB.in turnC.in chargeD.in time(2)atmosphere n.大气层，大气 the atmosphere气氛，氛围 a comfortable/pleasant atmosphere The tea

6、cher tries to create an atmosphere in class his students can practice their speaking skills.(福建福建)She has a gift for creating an atmosphere for her students allows them to communicatefreely with each othel.A.which B.where C.what D who(2)presence n.存在；出席，在场in the presence of sb.=in sb.s presence 当着某人

7、的面例“Raj feels rather awkward in the presence of ladies.present adj.出席的，在场的；现在的，当前的（3）allow v.允许，许可allow doing sth.允许做某事例：We donts allow smoking here.allow sb.to do sth.允许某人做某事例：He wonts allow himself to fail.(4)dissolve into (使)溶入，(使)溶解；(使)融化成例:Snow and ice dissolve into water(5)make it possible for

8、 sb.to do sth.句型句型：vt+(形式宾语)+adj./n+(for sb.)to do sth(可变)vt:make,think,consider;,find,feel,judge例:I dont think it necessary to argue with him.They make it a rule to read English words everyday.I dont think it worthwhile going to such a place.例1:The difference in thickness and weight from the earlie

9、r version makes the iPad4 more comfortable .A held B holding C be held D.to hold例2：Nowadays people sometimes separate their waste to make it easier for it .A.reusing B reusedC.reuse D.to be reused做题小技巧：去掉形式宾语it，变换成正常语序3.They multiplied and filled the oceans and seas with oxygen,which encouraged the

10、later development of early shellfish and all sorts of fish.它们繁殖起来就使得海洋充满了氧气，这为早期的贝类及其他各种鱼类的发育进一步创造了条件。(1)multiply v.乘，迅速增加；(使)繁殖 例：multiply 2 and 4 together you get 8 multi-多 multicultural adj.多元文化的 multimedia adj.多媒体的 multinational adj.跨国的，多民族的(2)encourage vt.鼓励，鼓舞encourage sb.to do sth.鼓励某人做某事 激励，

11、促进High prices encouraged farming.高价格刺激 了农业encouraging adj.令人鼓舞的encouragement n.鼓舞，鼓励courage n.勇气discourage vt.使泄气4.They laid eggs too and existed on the earth for more than 140 million years.However,65 million years ago the age of the dinosaurs ended.Why they suddenly disappeared still remains a mys

12、tery.它们也生蛋，在地球上生存了1.4亿多年。然而,6500万年前，恐龙时代结束了。它们为什么会突然灭绝至今仍是个谜。词形词形含义含义过去时过去时过去分词过去分词现在分词现在分词lie说谎说谎liedliedlyinglie躺，位于躺，位于laylainlyinglie放置；下蛋放置；下蛋laidlaidlaying(2)exist vi.存在；生存 exist on 靠生存existence n.存在existent adj.存在的，实际的 n.例：remain a beginner（3）adj.例：remain silent doing 例：remain standingremain+

13、done 例：remain untouched to be done 例：remain to be seen 介词短语介词短语 例：remain in London5.Thus they have,in their turn,become the most important animals on the planet.于是，他们接着成为这个行行上最重要的动物。（1）thus adv.因此，这样（2）in ones turn 轮到某人例：When it was in my turn,I was too excited to speak.in turn 依次；反之，反过来by turns 轮流；

14、交替地take turns to do sth./in doing sth.轮到某人做某事(广东汕头)A heavy learning burden leads to unhealthy behaviors such as poor eating habits,which damage the health of students.A.in its turn B.in returnC.in turn D.by turns轮到它的顺序；作为回报；反之；轮流6.They are putting too much carbon dioxide into the atmosphere,which pr

15、events heat from escaping from the earth into space.他们把过多的二氧化碳释放到大气层中，这使得地球上的热不能释放到太空中去。（1）prevent v.阻止，预防prevent sb./sth.(from)doing sth.主动句中主动句中from可以省略，可以省略，stop sb./sth.(from)doing sth.被动句中不能省略被动句中不能省略 keep sb./sth.from doing sth.protect sb./sth.fromdoing sth.保护免受例5：China recently tightened its

16、waters control near the Huangyan Island to prevent Chinese fishing boats from in the South China Sea.A.attacking B.having attackedC.being attacked D.having been atacked译文：最近，中国加强对黄岩岛附近水域的管控；以防止中国渔船在南海受到攻击。7.When life will continue on the earth for million of years to come will depend on whether this problem can be solved.在未来的数百万年终，生命能否在地球上延续取决于这个问题能否得到解决。（1）depend v.依靠，依赖depend on=count on=rely on sb.信任，依靠某人It all depends.看情况例：-How often do you eat out?-_,but usually once a week.