1、Unit4 Period3编写：李慧学习目标： 1熟记和使用本节六个词组；2能熟练相关短语 自主合作探究：6exist vi.存在；生存They laid eggs too and existed on the earth for more than 140 million years.(P26)它们也生蛋，在地球上生存了一亿四千多万年。归纳拓展： exist in存在于 exist on靠生存 There exist(s)/existed.某地有/存在existence n存在；生存 come into existence开始存在；成立 in existence现存的；现有的There ex
2、ists a tall tree in front of my home. 译： 小试牛刀： 用exist的适当形式填空He doesnt believe in the_ _of ghosts.Did huge animals_ _on the earth a long time ago?7give birth to产生；分娩.because they gave birth to young baby animals and produced milk to feed them.(P26)因为它们生出幼仔，用自己的母乳喂养。归纳拓展： at birth出生时 by birth天生地；生来；在血
3、统上 Babies look the same at birth. 译： Im a Chinese by birth. 译： 小试牛刀： 用birth的短语填空他说的话引起了一场争吵。 What he said_ _a quarrel.据说杰克逊生来就是黑人。Jackson was said to be a black man_ _.8in ones turn轮到某人；接着Thus they have，in their turn，become the most important animals on the planet.(P26)它们的时代到来了，它们成了这个行星上最重要的动物。When
4、it was in my turn，I was too excited to speak. 译： 归纳拓展： in turn依次；轮流；因此；因而 by turns轮流；依次take turns to do sth./in doing sth.轮流做某事It is sb.s turn to do sth.轮到某人做某事The girls names were called out in turn. 译： 小试牛刀： 介词填空They should take turns_ _looking after their old mother.The new couple of lovers did h
5、ousework_ _ turns.9prevent.from.阻止，制止They are putting too much carbon dioxide into the atmosphere，which prevents heat from escaping from the earth into space.(P26)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。归纳拓展： prevent /stop/ keep+ +宾语+from doing 阻止.干某事protect.from(against).保护不受侵袭(from后接能带来伤害或损害之物)【提示】其中k
6、eep后的from不可省 ，prevent /stop后from可省，用于被动语态中时，三个短语from都不能省略。）小试牛刀： 单句改错Nothing could prevent him to go out even though its bad weather._The plan can be prevented being carried out. _他们没有阻止他发表自己的观点。译：_10So whether life will continue on the earth for millions of years to come will depend on whether this
7、 problem can be solved.(P26) 所以，在未来的数百万年中，生命能否在地球上延续取决于这个问题能否得到解决。此句为主从复合句。句中两个whether分别引导了两个名词性从句，分别在句中作主语及介词on的宾语。It remains to be seen whether or not this idea can be put into practice.(whether引导主语从句)这一想法能否付诸实践还有待于观察。Ill see whether shes at home.(whether引导宾语从句)我来看看她在不在家。思考：if 与whether的用法（什么时候只用wh
8、ether不用if ）小试牛刀： 完成句子他喜不喜欢并没有什么关系。It matters little_ _ 达标练习：I.按要求完成句子1. Nobody knows when the earth (形成)2.我们轮流做家务。 3.They were stopped/prevented from entering the burning building.译： 。4.她拿不定主意是该留下来还是离开。She was uncertain_.5.这是最令人迷惑的问题之一。This is _ _problems. II.用介词填空1.他靠卖水果生存。.He exists selling fruits. 2.使我们大为高兴的是，我姐姐生了个健康的男孩 our great joy，my sister gave birth a healthy boy. 版权所有：高考资源网()
