单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,Unit 4 Global warmingUnit 4 Global warming,Unit 4 Global warmingUnit 4 Gl,人教版高二英语选修六Unit-4-Global-warming-Grammarppt课件,To learn the use of the emphatic“it”and its sentence form“It is/was that/who”.,To learn the use of the emphat,观察下面几组句子中,it,的用法,然后加以总结。,1.,【,语境展示,】,a.,It,was cholera,that,killed him.,b.,It,was Iris,that/who,found him there.,c.,It,sLawrence,that/who/whom,you should be talking to.,d.,It,was three weeks later,that,he heard the news.,【,归纳,】,it,用在强调句中，可以对句子中除谓语以外的成分加以强调。,观察下面几组句子中it的用法,然后加以总结。【归纳】,强调句型的基本结构是：,It is/was+,被强调部分,+that/who/whom+,句子的其余部分,，被强调部分指人时，用,who(,强调宾语也可用,whom),或,that,，指事物时用,_,。,that,强调句型的基本结构是：that,2.,【,语境展示,】,a.,Was it,in this year,that,the war,broke out?,b.,Is,it,Tracy,that/who/whom,you,are looking for?,【,归纳,】,强调句型的一般疑问句,形式是：,Is/Was it+,被强调部分,+that/who/,whom+,句子的其余部分,。,2.【语境展示】,3.,【,语境展示,】,a.,Why,is it that,everyone thinks he is,selfish?,b.,What was it that,they fought for?,【,归纳,】,强调句型的,特殊疑问句,形式是：,_,+is/was it that+,句子的其,余部分,。,疑问词,3.【语境展示】疑问词,4.,【,语境展示,】,a.,It,was because,I wanted to buy a dictionary that I went to town yesterday.,b.,It,is what,he said just now that makes me angry.,【,归纳,】,强调句型也可强调状语从句、名词,性从句等。,4.【语境展示】,5.,【,语境展示,】,a.,It must be,your mother,that/who/whom,you are thinking of.,b.,It might be,my two sisters,that/who,know her best.,【,归纳,】,在强调结构中，,be,前可使用表示推,测的情态动词。,5.【语境展示】,6.,【,语境展示,】,a.,It is not until,the end of the year that the traffic laws will take effect.,b.,It was not until,he was thirty that he started to paint.,【,归纳,】,not.until,句型的强调句的形式是：,It is/was not until+,被强调部分,+that,+,句子的其余部分。,6.【语境展示】,强调句型与其他句型的比较。,1)It is true that I like music.,2)It is music that I like.,3)It is 3 years since I came to No.1 Middle,School.,4)It is at 10:30 that we have our lesson.,5)It was 10:30 when we had our lesson.,6)It is in this school that I got my first,scholarship.,7)It is this school where we study.,强调句型与其他句型的比较。,【,归纳,】,一、强调句与主语从句句型的区别：,从形式上都有：,It isthat,，所以根据就,是把强调结构标志去掉后，原句在结构意,义上不成立则是,_,结构与意义,仍然成立的则是,_,。,主语从句,强调句,【归纳】主语从句强调句,二、当,it,泛指时间或地点时，常用以下句型：,It is/was+,时间段,+since,从句（一般过去时,/,过去完成时）,It was+,时间点,+when,从句（一般过去时）,It was+,时间状语,+that,强调句,It is,地点名词,+where,从句（定语从句）,It is+,地点状语,+that,强调句,二、当it泛指时间或地点时，常用以下句型：,Fill in the blanks.,Today I want to tell you a story._ is very interesting.One day I attended my class as usual._ was so cold that I closed the door.We were having class when suddenly someone knocked the door.We all wondered who _ was because no one was absent that day.It was tough _(guess)who it really was.It was clear _ no one knew.So I went up to the door and opened _ curiously.,It,It,it,to guess,that,it,Fill in the blanks.ItItitto g,It was the headmaster _ stood outside.We were confused.He said to me.“I find _ unbelievable that you are late for class again”.It took me a few seconds _(understand)what he said.It was no use _(argue)with him.I smiled,“Sorry,headmaster,you mad e a mistake,again.”He went away disappointedly.Our class burst into laughter.Actually I hate _ when someone interrupts my class.,who/that,it,to understand,arguing,it,It was the headmaster _,Finish Exercise 2 on page 29:,Rewrite each sentence with,It is that/who,to give more emphasis to the underlined part.,Finish Exercise 2 on page 29:,Scientists,warned that greenhouse gases would warm the earth by trapping heat energy in the atmosphere.,It was scientists who warned that greenhouse gases would warm the earth by trapping heat energy in the atmosphere.,Scientists warned that greenho,2.,The greenhouse effect,gives the earths surface the average temperature of 15,.,It is the greenhouse effect that gives the earths surface the average temperature of 15,.,3.Much of the energy used to light and heart our homes comes from,fossil fuels,.,It is fossil fuels that much of the energy used to light and heat our homes come from.,2.The greenhouse effect gives,4.,The developed countries,consume the most energy in the world.,It is the developed countries that consume the most energy in the world.,5.Carbon dioxide has the tendency to stay in the atmosphere,for centuries,while other greenhouse gases stay in the atmosphere only for a day or less.,It is for centuries that carbon dioxide has the tendency to stay in the atmosphere while other greenhouse gases stay in the atmosphere only for a day or less.,4.The developed countries con,6.Low-lying countries feel,their very existence,is in danger from rising sea levels.,It is their very existence that low