Answer keys for Ex.1 on Page 11: VerbAdjectiveNoun weaken strengthe n beautify digestive balance amazement strong amazing weakness beautiful weak strength beauty balance digestdigestion balanced amaze

Answer keys for Ex.2 on Page 12: Alternative words and expressions Words and expressions from the text should run away after … something to make … wish to know … get rid of something parts of plants … changing food into … proper amount of … ought to get away with slimming foods curiosity throw away fibre digestion balanced diet

Answer keys for Ex.3 on Page 12: 1. slim 2. research 3. weakensses 4. cucumber 5. mushrooms 6. body-building 7. raw

Modal Verb (2)

ought to  ought to 用于表示 " 想必会 "( 语气较 must 弱 ) ： 1. 他们想必已到那儿了。 They ought to be there by now. 2. 他最好不要抽烟了。 He ought to stop smoking.  多数情况下， ought to 可与 should 互换使 用。  Ought to 的反意疑问句用 shouldn’t 替代。

13. You ought to have helped him with his English, ________ you ? A. won’t you B. ought not you C. shouldn’t you D. wouldn’t you

比较 had better, should & ought to  三者均表示建议，意为 “ 应该 ” ， “ 应当 ” 或 “ 最 好做 …”.  三者的语气程度为渐强。  Had better 指一般性的建议，最弱。  Should&ought to 含义相近，常可互换。区 别在于， ought to 常指特殊情况下的 “ 应当 ” 。 Should 则指一般情况。见下页例句。

 You ought to help him because he is in trouble now.( 语气强，有命令意味。 )  You should have a rest after finishing your sports. （一般性建议）  You ought to call the police when you find something wrong in your house.  He should take care of the babies tonight.

have to  have to 表示客观需要去做的事情，意为 “ 必须，不得不。 ”  I have to get the station early to catch the first train.  We missed the bus so we had to walk home.  We have to overcome all kinds of difficulties.

 Have to 有多种时态。常见的有：一般将来时，  We will have to gather at the school gate at 7 tomorrow.  一般现在时  I have to take more money with me because my gf has so much to buy.  一般过去时  Finally, we had to give up our idea to hold a picnic outside as it rained for a whole afternoon. have to （考点）

shall 用于第一，三人称疑问句， 征求意见或请求 shall 第二，三人称 陈述句, 命令, 警告, 允诺, 威胁 should 表劝告，建议，命令，顺理成章的 ＝ ought to 疑问句中常用 should 代替 ought to ought to 表应该，语气＞ should 美语中， ought to 用于否，疑句时 to 可省 shall, should &ought to

Need I do …? Yes, you must. No, you needn’t. dare & need 情态动词实义动词 dare 否，疑，条 dare not do 否, 疑 don’t dare to do don’t dare do 不用于肯定句肯： dare to do need 否，疑 needn’t do (don’t) need sth (don’t) need to do 肯： must, have to, ought to, should

Must they do…? Yes, they must. No, they needn’t/don’t have to. must & have to must have to 主观／客观 主观 客观 时态 现在，将来 多种 表推测 √ × 询问意愿 √ × 否定意 禁止，不允许 不必

 must 表主观意志，而 have to 表由于客观因 素不得不做完成的事情。  Must 没有过去式，除在间接引语中可表示过 去的时间。在直接引语中表示过去的时间用 had to 代替。  I told her that she must give up smoking.  She said, “We had to get everything ready that night.” 比较 must & have to

注意对 need 问句的回答 : --Need I finish the work today? --Yes, ________________. No, ________________. you must you needn’t you don’t have to

needn’t 对其它情态动词的回答 : --Shall I tell John about it? --No, you __________. --Must we do it now? --No, you __________. needn’t (don’t have to) needn’t (don’t have to)

 Could I borrow your dictionary?( 委婉 ) ---- Yes ， you can/may. Sure. Go ahead. Please yourself.  May I take this seat?( 第一人称疑问句 ) Yes, you may. No, you mustn’t.

高考链接 1.--Is John coming by train? --He should, but he ____ not. He likes driving his car. A. must B. can C. need D. may 2.It has been announced that candidates( 候选人 ) ____ remain in their seats until all the papers have been collected. A. can B.will C. may D. shall 3.--I heard they went skiing in the mountains last winter. --It ____ true because there was little snow there. A. may not be B. won’t be C. couldn’t be D. mustn’t be

Practice 1: 高考考题专练 1. I thought you _____like something to read, so I have brought you some books. A. may B. might C. would D. must 2. Where is my pen? I ____it. A. might lose B. would have lost C. should have lost D. must have lost 3. I didn’t hear the phone. I ___asleep A. must be B. must have been C. should be D. should have been B D B

4. ---There were already five people in the car, but they managed to take me as well. ----It ____a comfortable journey A. can’t be B. shouldn’t be C. mustn’t have been D. couldn’t have been 5. It’s nearly seven o’clock. Jack ___be here at any moment. A. must B. need C. should D. could D C

情态动词考题 : Did the train arrive in time? ----No. It _______ two hours ago. A. must have arrived B. ought to have arrived C. must arrive D. ought to arrive 2. "Must I drive to his house and pick up the children?" "No,." A. you shouldn't B. you might not C. you needn't D. you mustn't B C

3. We didn't see Tom at the meeting yesterday. He it. A. mustn't have attended B. cannot have attended C. needn't have attended D. would have not attended B

4. You ________ such a long composition. The teacher only asked for 300 words. You have written 600. A. mustn’t have written B. couldn’t have written C. needn’t have written D. do not have to write C

5. There is someone knocking at the door. it be Tom? A. can B. must C. should D. ought to 6. Two years ago, my husband bought me a bicycle. If you live in town, it is often faster than a car and you worry about parking. A. must not B. may not C. should not D. don't have to0 A D

Assignment 1. Summarize the rules of the modal verbs in your own way. 2. Finish the exercises of “Discovering useful structures” on Page