新概念第二册17课.ppt

Lesson 17 Always young Listening to the tape and answer the questions: Key structures 情态动词must must 主观 必须 have to 客观 have got to 客观 现在must do  表推测 过去must have done eg. 你必须少抽些烟。 You must cut down on smoking. I’m afraid I must go now. eg. Must you leave now? Yes, I must./ No, I needn’t. Key structures must与have to一般可互换，但表示“必须” 时， must着重说明主观看法， have to比较强调客观需要。 eg. I must tidy up the room. 我必须打扫一下房间。（主观想法） I have to tidy up the room. 我不得不打扫一下房间。（客观需要） Key structures have to有人称、数、时态的变化，而must没有eg. I had to go to see the dentist. She had to go shopping yesterday. 在否定结构中： don‘t have to　 表示“不必”　　　　　　mustn’t　　　　表示“禁止” eg. You don‘t have to tell him about it.　 你不一定要把此事告诉他。 You mustn‘t tell him about it.　　　　 你一定不要把这件事告诉他。 Key structures must be可用来表示对现在情况的推测，（只有在肯定句中能这样用，这种揣测比may be表示的要肯定得多）： eg. He must be working in his office. She must be over forty. 试比较： eg. He must be staying there.　 他现在肯定呆在那里。 He must stay there. 他必须呆在那。 Difficulties grow vi.生/成长，渐渐变得，增长，增高 vt.种植，栽培，培育 e.g. Farmers grow rice. e.g. Money doesnt grow on trees. Absense makes the heart grow fonder. grow up 长大；长成；成年 * She is an actress, too. Which picture do you think is her now? Now before She often appears on the stage as a young girl. 徐若瑄 She is an actress，too. Which picture do you think is her now? Now 16 years ago Does she look young? Do you think how old she is? She must be at least…… at least at + ( the ) + 最高级——表示“最”，“至” at most 至多，最多 at first 最初，首先 at the earliest 最早 at least 至少，最少，起码 at last 最后，终于 at the latest 最晚 e.g. There can be no more than fifty people in the audience at ( the ) most. At least two hundred have left. discussion 1.How old is your mother/father? 2. Do they look young? 3.Does your mother have any good wa