1、Book 6 Unit 4 Global warmingPeriod 4 Learning about Language学习目标 1.熟练掌握下列词汇和短语的用法并能造句。 2.掌握下面的语法知识并会应用。自主合作探究11The greenhouse effect gives the earths surface the average temperature of 15. (教材P29)温室效应使地球表面的平均温度保持在15摄氏度。【品味经典】1) He averaged nine hours work a day. 他平均每天工作九小时。2) Marys school work is we
2、ll above (the) average. 玛丽的学习成绩远远高于平均水平。【归纳拓展】average adj.平均的；普通的 n平均 v平均数为；算出平均数on (the/an) average平均来看 above / below (the) average高于/ 低于平均水平【语境活用】完成句子汤姆的功课在学校是中游以上水平。Toms work at school is .一般来说，男子比女子吸烟多。 ，men smoke more cigarettes than women.2Lowlying countries feel their very existence is in dan
3、ger from rising sea levels.(P29)一些地势较低的国家由于海水的上涨而感到他们已陷入被海水淹没的危险之中。【品味经典】1) We do not believe in the existence of ghosts. 我们不相信真有鬼。2) The elephant is the largest land animal in existence. 大象是现有的最大的陆上动物。【归纳拓展】1) existence n存在；生存 exist v存在；有；生存 existent adj.存在的；现行的2) in existence存在 come into existence
4、产生；出现 bring.into existence使产生3) exist in存在于之中 exist on靠生活/生存【语境活用】完成句子无法证明上帝的存在。It is impossible _ .这种风俗什么时候形成的？When did the custom _ ？自主合作探究2 it的用法()在语言的使用过程中，有时我们要根据具体语境的需要对句中的某些部分进行强调，这时候我们就需要一种特殊的句型强调句。1强调句型的基本结构: It is/was被强调部分that/who其他成分. 强调句型中的it is/was和that无实际意义，去掉后，句子结构仍然完整,不缺少任何成份。1) It i
5、s what you do that matters. 重要的是你的行动。2) It was John who/that bought an old bike yesterday in a marketplace. 是约翰昨天在市场上买了辆旧自行车。2强调句型的一般疑问句式和特殊疑问句式(1)一般疑问句式：Is/Was it被强调部分that/who其他成分？Was it during the Second World War that he died? 他是二战期间死亡的吗？(2)特殊疑问句式：特殊疑问词is/was itthat/who其他成分？Why is it that you put
6、 off the meeting? 你为什么推迟会议呢？3对not.until结构的强调not.until结构的强调句型为“It is/was not until.that.”在这一固定句型中，由于not已经前移，that后只能用肯定形式。He didnt go to bed until ten oclock. It was not until ten oclock that he went to bed.4强调句型与其他从句相结合强调句型与其他从句相结合是近几年来的重要考点，要注意分清强调句型和其他句型。1) Ive forgotten where it was that I put the
7、 dictionary. 我忘了把词典放哪里了。2) It was in the lab which was taken charge of by professor Harries that they did the experiment.他们是在Harries教授管理的实验室里做那个实验的。5与强调句型容易混淆的句型(1) 强调结构与It is时间since从句。It is.since.表示“自从以来已有(时间)”。 注意：两个句型中的时态一般不同，试比较：It was two years ago that I began to learn English. 我是两年前开始学英语的。It
8、is/has been two years since I began to learn English. 自从我开始学英语到现在有两年了。(2) 强调结构与It is/was时间when从句It is/was.when.中it指时间，when 引导的是时间状语从句。试比较：It was at midnight that I got back home yesterday. 昨天午夜我回到了家里。It was midnight when I got back home yesterday. 当我昨天回到家里时，已经是午夜了。(3) 强调结构与Itwas/will be一段时间before从句该
9、句型中的时间常为long，a long time，years，months，weeks，days，hours等时间段。试比较：It was two years before he came back from abroad. 过了两年他才从国外回来。It was two years later that he came back from abroad. 两年之后他才从国外回来。达标练习 .用强调句型改写下列句子。1He didnt attend the meeting because he was ill.It was _ he was ill _ he didnt attend the m
10、eeting.2When did you call me yesterday? When you called me yesterday?3Did the Second World War break out in 1939? the Second World War broke out?4I dont know why you want to change your mind.I dont know _ you want to change your mind.5What he said disappointed me. It was _ he said _ disappointed me.完成句子1我不知道到底是什么使她与众不同。I dont know _ _ makes her different from others.2直到临近信的末尾，她才提到了她自己的计划。It was _ she mentioned her own plan.1.