Unit 2 Healthy Lifestyle Discover Useful Structures课件-2023-2024学年高中英语人教版（2019）选择性必修第三册

Discover Useful Structures Unit 02 Healthy Lifestyle 新人教选择性必修三 Learning Aims After this period ,students will be able to: 1. To master the different forms and use of the infinitive; 2. To understand the differences of the Infinitive and the gerund as subject; 3. To use the Infinitive as subject to discuss healthy lifestyles. B. Teaching Emphases & difficulty 1. Help students to explore the use of the infinitives as subject; 2. Make sure students use the infinitive correctly in specific context. B. Lead-in Analyze what does the underlined part serve as in each sentence and translate them into Chinese. To prevent harmful habits like these from dominating a teenager’s life is essential. (para 1) To change bad habit is never easy,even with many attempts. (para 2) 改变不良习惯从来都不是一件容易的事情，即使你三番五次地尝试。 防止此类有害习惯主宰青少年的生活是至关重要的。 系动词 表语 主语 主语 系动词 表语 to do 不定式放在句首作主语 B. useful/turn to/fitness consultant/for advice It is useful to turn to a fitness consultant for advice. illegal /dangerous/take /drugs It is illegal and dangerous to take drugs. harmful /often /skip /breakfast It is harmful to often skip breakfast. Lead-in B. Lead-in It took the surgeon three hours to finish my mother’s lung surgery. To join the People’s Liberation Army, it is required for men to shave off their beards. It was not polite to disturb your neighbours with loud music last night. Read the following sentences and analyze what does the underlined part serve as in each sentence. (activity 1) 形式主语 真正主语 形式主语 真正主语 形式主语 真正主语 用 it 作形式主语，放在句首，把真正的主语 — 动词不定式置于句后。 B. 练一练 1. Sometimes it’s better 　　　　 　（stay)calm when in trouble. 2. It was foolish 　　　　her to make such a mistake. 3. It is rude 　　　 　 him to say that to a lady. 4. It is difficult 　　　　teenagers to live alone in a foreign country. to stay of of for B. The difference between the infinitive and the gerund 不定式与V-ing作主语的区别 不定式作主语表示一次性的、具体的、将来的或未做的动作； 动名词作主语表示一般的、抽象的、泛指的或者已经完成的动作。 __________ (finish) the task in time is a great cha