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

UNIT 2 HEALTHY LIFESTYLE Infinitives as the subject Discover useful structures 1. However, during this period, it can be easy for some of them to form bad habits. 2. To prevent harmful habits like these from dominating a teenager’ s life is essential. 3. To change bad habits is never easy, even with many attempts. 4. After all, it is not easy to break bad habits. 5. When to hold the sports meeting has not been decided. Observe and Discover Look at the following sentences and pay attention to the infinitives. P36 【语法感悟】 ①在句1、4中，it是　　　　　　，代替后面的动词不定式短语。  ②在句2、3中，To prevent...和To change...都是动词不定式短语作　　　　　________。  ③在句5中，When to hold...是“疑问词+to do”结构，该部分在句中作　　　　　。  形式主语 主语 主语 e7d195523061f1c0f0ec610a92cff745ee13794c7b8d98f8E73673273C9E8BE17CC3D63B9B1D6426C348A354AD505654C28F453CD7C8F90EADD06C08281DAED7140E5AAAED5880ECE414DFB6A93B82BE019406867034C3A8500A4827DCF3FBF74A471B736410707E336A01C9ADC9BE02ACCB8DF2121D81636A067B8AE80C6AB6F014154F4E7B7247 总结 思考 位置 含义 本质 名词词性 不定式短语在句中做主语。 3 一【含义】 不定式作主语一般表示具体的或某一次的或将来的动作, 谓语动词用单数。 To know something about English is one thing; to know English is quite another. 懂一点英语是一回事；掌握英语完全是另一回事。 注：单个不定式作主语时，谓语用单数形式；两个及以上不定式作主语时，谓语用复数形式；但作为一个整体时，谓语用单数形式。 Where to go on a holiday and when to go for the holiday _____(have) not been decided. Where and when to go on a holiday ______(have) not been decided. have has 不定式作主语，有时根据表达的需要，可以在添加疑问代词或副词， 疑问代词：who，whom，what，which 疑问副词：when，where，how whether E.g. How to break the bad habit is the question. Where to go hasn't been discussed. It has not been decided whether to fly to Paris. ”疑问词+to do”作主语 【Practice】Use the correct forms of the words to fill in the blanks. When ________ (start) has not been decided yet. How ________ (use) the computer is the question. It has been decided where ________ (spend) our winter holiday. to start to use to spend 二【位置】 1. To prevent harmful habits like these from dominating a teenager's life is essential. 2. To change bad habits is never easy, even