Unit 2 Healthy Lifestyle Discover Useful Structures 课件 -2025-2026学年高中英语人教版选择性必修第三册

Unit2 Healthy Lifestyle Learning About Language Discover useful structures Pay attention to the red italicized infinitives and discuss the meanings and functions of the italicised infinitives. Lead-in 1 To change bad habits is never easy. 2 It took the surgeon (n.外科医生) three hours to finish my mother’s lung surgery (n. 外科手术). 3 To join the People’s Liberation (n. 解放) Army , it is required for men to shave off (剃掉,刮掉)their beards. 4 It was not polite to disturb(v. 打扰)your neighbours with loud music last night. 主语 主语 状语 主语 主语 1.不定式作主语通常位于______，表示具体的某次动作，谓语动词用______。 一、动词不定式作主语 ▶To see is to believe. 眼见为实。 （注意：当句子主语和表语都是非谓语时，通常要保持一致。） E.G.✅ Seeing is believing.（正确，都是动名词） ❌ To see is believing.（错误，不对称） Explore grammar 句首 单数 ▶It is impossible for them to complete the task in such a short time. 对他们来说,在如此短的时间内完成这次任务是不可能的。 ▶It was foolish of him to make such a mistake. 他真傻,犯这样一个错误。 2.动词不定式作主语一般表示某一次具体的动作,常用it作形式主语,而动词不定式是真正的主语,放在句末,以使句子保持平衡。常见句型: ①It is+adj.+for sb/sth+to do sth. ②It is+adj.+of sb+to do sth. 当形容词修饰动词不定式时，此时常用介词_____。 当表语形容词表示不定式的逻辑主语的性质或特征时，则用介词____。） for of 注意： ▶To learn English well and to master a skill _______ (be) very important for your future. ▶To jog every morning and to do some stretching exercises in the evening _______ (be) good ways to keep fit. ▶To love and to be loved ______ (be) the greatest happiness one can get. ① 两个及以上动词不定式作主语，谓语动词用复数形式。 ② 两个并列的不定式语义基本一致，谓语动词用单数形式。 is are are 动词不定式作主语一般表示具体的、特定的行为;而动词-ing形式作主语一般表示抽象的、一般的行为。如:Riding a bike can make a man smart. 骑自行车能使人敏捷。 【应用实践】根据汉语句意完成英语句子。 ①学好英语不容易。____ ______ ________ ______ is not easy. ②学生学习一门外语是必要的。 It is __________ ____ ________ ____ ______ a foreign language. ③他很自私,不为别人着想。 It was ________ ____ ____ ____ ____ think of others. To learn English well necessary for students to learn selfish of him not to 二、“疑问词+动词不定式”作主语 【观察思考】 ▶When to hold the meeting hasn’t been decided. 何时召开会议还没有确定下来。 ▶How to solve the problem is very important. 怎样解决这个问题是非常重要的。 ▶What to do next is not decided yet.下一步做什么还没有决定。 疑问词后可以加动词不定式构成一种特殊的动词不定式短语,可在句中作主语。 【应用实践】根据汉语句意完成英语句子。 ①何时离开还没有决定。______ ____ ______ has not been decided. ②如何开始比到哪里停止还困难。 ____ ____ ______ is more difficult than ______ ____ ______ . When to leave How to begin where to stop 三、动词不定式作主语时的语态 ▶It was an honour for him to be chosen as head of the medical team. 他被选为医疗队队长是一种荣幸。 ▶To finish the task will take a long time.完成这项任务要花费很长时间。 【探究总结】 动词不定式作主语时,如果不定式和逻辑主语之间是主动关系应使用to do, 如果是被动关系应使用 _________。  【应用实践】单句语法填空。 ①It’s a pity __________ (keep) in the house in such fine weather.   ②It’s a great honour ____________(invite) to the banquet.  to be done to be kept to be invited 拓展1 It is an honour to give a speech on behalf of my school. It is a pity to miss the chance to see your show. It is our duty to do that. 常用句型：It is + n. + (for sb.) to do sth. 常见的名词有：pity, shame, pleasure, one’s duty, one’s job, fun, joy, good manners, bad manners等 拓展2 It took me more than an hour to do my homework yesterday evening. It will take us a lot of money to buy that house. 常用句型： It takes/took/will take sb. some time/money to do sth. 做某事花费某人多长时间(钱) 拓展3 一些不定式短语可用作独立成分，通常位于句首，有时位于句中或句末，要用逗号同其他句子成分隔开。 to begin/start with 首先 to sum up 总而言之 to conclude 总而言之 to tell the truth 说实话 to be frank 坦白地说 to be honest 说老实话 to be brief 简言之 Practice Join the words to make full sentences, and then join the sentences to make a paragraph. You can add your own sentences if necessary to make your paragraph more meaningful. 1. important / avoid / passive cigarette香烟 smoking It is important to avoid passive cigarette smoking. 2. will take / nutrition specialist专家 / a balanced diet menu / make / an hour / for you It will take an hour for a nutrition specialist to make a balanced diet menu for you. 3. useful / turn to / fitness consultant顾问 / for advice It is useful to turn to the fitness consultant for advice. Practice Join the words to make full sentences, and then join the sentences to make a paragraph. You can add your own sentences if necessary to make your paragraph more meaningful. 4. illegal / dangerous / take drugs毒品/药物 5. harmful / skip跳过 breakfast / often It is dangerous to take illegal drugs. It is harmful to skip breakfast (too) often. Practice Complete the conversations with the correct forms of the phrases in the box. 1. A: Hello, doctor. I want to lose weight(减肥), but I just can’t seem to do it. What can you do to help me? B: Well, first, it’s necessary to ________________ what you eat. Cut out(停止；切断) all fatty food and sugary(含糖的) drinks, and eat more fruit and vegetables. be in control of begin with, be in control of, make a choice, decide on, make up one’s mind 首先 控制；掌控 做出选择 选定 下定决心 Practice Complete the conversations with the correct forms of the phrases in the box. 2. A: I really need to ____________ a way to exercise more. I could use a fitness app, but my phone’s full. B: So delete a few files. I’m sure the app doesn’t take up(占据) much space. 3. A: Before exercising, always do a few warm-ups(热身活动) to ___________. B: I know. But then I always feel too tired to continue! begin with, be in control of, make a choice, decide on, make up one’s mind decide on begin with Practice Complete the conversations with the correct forms of the phrases in the box. begin with, be in control of, make a choice, decide on, make up one’s mind 4. A: Should I go for the pizza or the fried chicken? I hate _________________ like these. You know what — I’m going to eat both! B: Wow! Don’t eat too much junk food — you’ll get fat, I’ve actually __________________ to go on a diet(节食), so I’ll just stick to(坚持) the fruit salad. making choices made up my mind to do to do 作主语位于句首，在谓语之前 to do 作主语位于谓语之后，It作形式主语 疑问词+to do 构成不定式短语，作主语 和-ing 作主语的区别 To read without reflecting is like eating without digesting. It takes sb. time/money to do sth. It is + adj. + （for/of sb.） to do sth. It is + n. + (for sb.) to do sth. to do 表示具体的，将来的，一次性的动作 -ing 表示经常性、习惯性、抽象的动作 与疑问词who, whom, whose, what, which, when, where, how等连用 Summary THANK YOU $