Unit 2 Discover useful structures ppt课件-（2022新）人教版高中英语选择性必修第三册(1).pptx

1、NoImageNoImageNoImageNoImageNoImage新人教版选择性必修三Unit2Discover useful structuresInfinitives(3)as the subject1目目 录录CONTENTS2不定式做主语的用法巩固练习NoImageNoImageNoImageNoImageNoImage不定式做主语不定式做主语01翻译以下句子，补全方框下的小题。1.To see is to believe.2.To do morning exercises is useful for our health.3.It is interesting to play w

2、ith snow in winter.4.Its important for human beings to keep the balance of nature.1. 以上句子中动词不定式都是作 。2. 句(2)(3)(4)中it作 ，真正的主语是后面的 。主语形式主语动词不定式不定式作主语基本用法：一. 动词不定式作主语，位于句首，谓语动词用单数。1. To know yourself is difficult. 了解自己是很难的。2. To love and to be loved is the greatest happiness one can get. 爱与被爱是一个人能获得的最大

3、幸福。3. To look after these naughty boys is really difficult. 照看这些淘气的男孩真的很难。4. To save money now seems impossible. 现在存钱好像不可能。二. 为了避免头重脚轻，常用it作形式主语放在句首，作主语的不定式常置于句末。1. Its our duty to take care of the old. 照顾老人是我们的责任。2. It took me two months to finish the work. 我花了两个月时间来完成这项工作。3. It is against my princ

4、iples to do such a thing. 做这样的事违背我的原则。4. It is difficult to solve the problem. 解决这个问题很难。5. It was hard him to live on his small income.依靠他那点工资维持生活很难。6. It was careless you to leave your umbrella on the train.你真粗心，把伞忘在火车上。在 It is+adj.+for sb to do.句型中，这类形容词常表示动作的特征， 比如：easy ,difficult, comfortable, p

5、leasant, dangerous， tiresome, interesting , heavy等。在 It is+adj.+of sb to do.句型中，这类形容词常表示人的性格、品质，如good，kind，nice，foolish，polite，considerate，careless等。forof注意：三. 疑问词how, what, when, where, which连用构成不定式短语做主语。1. Where to hold the meeting is still unknown. 哪里开会还未知。2. How to solve the problem has not been

6、 decided yet. 如何解决这个问题还未决定。3. How to prevent them from swimming in this river is a problem. 怎样阻止他们在这条河里游泳是一个问题。4. What to do and how to do it are your own business. 去做什么以及怎样去做，是你自己的事。四. 不定式和动名词作主语的区别。1. 不定式做主语表示具体的某次动作, 特别是指将来的动作；动名词做主语表示比较经常性的、一般性动作。1. To teach you the uses of the infinitive is my

7、job today. (表具体行为) 教你们不定式的用法是我今天的工作。2. Teaching is my job. (经常性行为) 教学是我的工作。2. 如果主语用不定式，表语和宾语也用不定式；主语用动名词，表语和宾语也用动名词，这在英语中称为对称性。1. To see is to believe.Seeing is believing. 眼见为实。2. It is better to stay home than to go out. 待在家里比出去要好。3. 在It is + no use/no good/useless/fun/interesting/foolish/a waste o

8、f time/ a pleasure. . . 句型中常用动名词形式作真正的主语。1. It is no use crying over the split milk. 覆水难收。2. It is a waste of time waiting here doing nothing. 无所事事地等待是浪费时间。3. It is no good taking this medicine. 服用这种药没有用。注意：如果该句型中用了for引出不定式的逻辑主语，就只能用不定式。It is no good for us to do that exercise.我们做那种练习没有好处。巩巩 固固 练练 习

9、习02.单句语法填空单句语法填空1.Sometimes its hard (let)go.For many British people，that can apply to institutions and objects that represent their countrys pastage-old castles，splendid homes.and red phone boxes.(2020江苏卷阅读江苏卷阅读B)2.He will find is easy to make friends in this city.3. (get) there by bike will take u

10、s half an hour.4.It was a big deal for us (load)up and go to the local library，where my kids could pick out books to read or books they wanted me to read to them.(2020全国卷全国卷阅读阅读D)to letitTo getto load5.Its very nice you to get me two tickets for the World Cup.6.Its necessary you to give up smoking.7

11、.How long did it take you (finish)the work？8.As is known，only (work) hard leads to happiness.9.He says its not easy (convince) people that nutria fur is green，but he has no doubt about it.(2020全国卷全国卷阅读阅读C)10.How (learn) English well is important.offorto finishworkingto convinceto learnII. Complete t

12、he sentences.1. _in ten months was a great achievement. 10个月内就盖成那座楼是一个了不起的成就。 2. It is not very good for you _. 抽这么多烟对你(身体)很不好。3. _ is to be respected. 尊重别人就是尊重自己。4. It is not an easy thing _. 精通一种语言是不容易的。5. It made us very angry _. 听他那样谈话我们非常气愤。 To complete that buildingto smoke so muchTo respect othersto master a languageto hear him talk like that