1、Answer keys for Ex.1 on Page 28:Checking answer I(2m)wordWhich usedtrendfuelstateconsumeglance12221Answer keys for Ex.2 on Page 28:Checking answer II(3m)Discovering useful structuresPage 29Answer key for exercise 1:1.It was a scientist called Charles Keeling,who made accurate measurements of the amo
2、unt of carbon dioxide in the atmosphere from 1957 to1997.2.it is the burning of more and more fossil fuels that has resulted in this increase in carbon dioxide.强调句型强调句型强调句型，你掌握了吗？强调句型，你掌握了吗？一、一、It is/was+被强调部分被强调部分 +that+剩余的部分剩余的部分 被强调部分是人被强调部分是人 who/whom/that +剩余的部分剩余的部分 注意注意 1.强调句的连接词一般只用强调句的连接词一般
3、只用 that；强调人时，强调人时，可用可用who(主语主语)或或 whom(宾语宾语).2.强调句的时态一般为强调句的时态一般为“It was+that”3.强调句的一般疑问句句型：强调句的一般疑问句句型：Is/Was+it+所强所强调的部分调的部分+that/who/whom?4.强调句的一般疑问句句型：疑问词强调句的一般疑问句句型：疑问词+所强调的所强调的部分部分+that/who/whom?1.我是在街上遇见她的父亲的。我是在街上遇见她的父亲的。(强调在街上强调在街上)2.你是你是8点开始工作的吗？（强调时间点开始工作的吗？（强调时间）3.正是因为她病了，他们才没见她做这项工作。正是因
4、为她病了，他们才没见她做这项工作。4.他为什么不能回答这个问题？他为什么不能回答这个问题？It was in the street that I met her father.Was it at eight oclock that you began to work?Because she was ill,they didnt ask her to do the job.It was because she was ill that they didnt ask her to do the job.Why was it that he couldnt answer the question.（
5、强调原因）（强调原因）判断是否是强调句是，可把判断是否是强调句是，可把 It is/was that 去去掉，剩余部分在不增减任何词的情况下还是一掉，剩余部分在不增减任何词的情况下还是一个完整的句子，那么这种句子是强调句。个完整的句子，那么这种句子是强调句。It was in the street that I met her father.In the street I met her father.It was because she was ill that they didnt ask her to do the job.Because she was ill,they didnt a
6、sk her to do the job.二、二、not.until.的强调形式的强调形式:It is not until+被强调部分被强调部分+that.“直到直到才才”，主要用于强调时间状语的强调句型。主要用于强调时间状语的强调句型。I didnt realize she was a famous film star until she took off her dark glasses.Not until she took off her dark glasses did I realize she was a famous film star.It was not until she
7、took off her dark glasses that I realized she was a famous film star.三、三、句子句子的强调手段的强调手段：do/does/did+动词原形动词原形e.g 我的确相信他是老实人。我的确相信他是老实人。I do believe that he is an honest man.他们昨天的确去看过你，但没见到你。他们昨天的确去看过你，但没见到你。They did go to see you yesterday,but failed to meet you.四、四、What+从句从句+is/was 是名词从句结构，常用来强调主语、宾
8、语。是名词从句结构，常用来强调主语、宾语。e.g他最希望的是成为一名飞行员。（强调宾语）他最希望的是成为一名飞行员。（强调宾语）What he wishes most is to become a pilot.所叙述的是所叙述的是现在或者将现在或者将来来发生的事情发生的事情What+从句从句 is 所叙述的是所叙述的是过去过去发生的发生的事情事情What+从句从句 was What interested me most was the beautiful scenery.给予我们鼓励的是他为我们树立的榜样。给予我们鼓励的是他为我们树立的榜样。（强调强调主语主语）What encouraged
9、us was the example he set for us.What+从句从句+is/was 使我最感兴趣的是那美丽的风景。使我最感兴趣的是那美丽的风景。（强调主语强调主语）巩固练习：巩固练习：1.It was what he said _disappointed me.2.Is it in the factory _ this type of cars are produced?3.Is it the factory _ this type of cars are produced?4.It is I _ is singing in the garden.8.It is in the
10、west of China _ there is no doubt _ it is going to rain tomorrow.thatthatwherewhowherethat10.It was the training _ he had as a young man _ made him such a famous writer.9.It was 1969 _ the American astronauts succeeded in landing on the moon.whenthatwhen1.It is scientists who warned that greenhouse
11、gases would warm the earth by trapping heat energy in the atmosphere.2.It is the greenhouse effect that gives the earths surface the average temperature of 153.It is fossil fuels that much of the energy used to light and heat our homes comes from.4.It is the developed countries that consume the most
12、 energy in the world.5.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.Answer key for exercise 2 on page 29:6.It is their very existence that low-lying countries feel is in danger from risin
13、g sea levels.7.It is environmentalists who have tried to stop the earths temperature rising.8.It is future climate changes and their effects on our environment that scientists want to find out about.9.It is by several metres that the level of the sea could rise in the years ahead because of global warming.10.It is outer space that might provide us with new energy sources in the future.
