Unit 3 Seeing a doctor Part B must的用法.ppt

1、Unit 3 Seeing a doctor Part A must的用法,must后接动词原形; 没有人称和数的变化; 不能单独作谓语, 与后面的动词共同作谓语; 其否定形式在后面直接加not。,Must,must / must not,1. must表示必须。 You must do your homework first. 2. must表示 一定(肯定性推测 ) 。 He must be at home.,must的用法:,What do the signs mean? Do you know?,You must not cycle.,You must be careful.,You

2、must turn left.,You must not enter.,You must pay ten yuan.,You must keep silent.,You must not turn right.,You must not smoke.,must / must not,1. mustnt表示禁止(不准；不允许) You mustnt smoke here. 2. 以 must 开头的疑问句，其否定回答要用 neednt. - Must I clean the classroom now? - Yes, you must. No, you neednt.,must not的用法:,

3、Have a try!,1. Must I carry your bag for you? 2. Must I open the door? 3. Must I get you a chair? 4. Must I switch on the TV? 5. Must I borrow your new bicycle?,Answers: NO, you neednt. Yes, you must. Yes, you need. NO, you neednt. NO, you neednt.,1.How can he get there ? 2.Must Li Lei go there by b

4、us ?,A：Excuse me, can you tell me ? B：About minutes walk。 A：You must .,A：Excuse me, can you tell me ? B：About minutes walk。 A：You must .,用适当的情态动词填空： 1.I cant play with you. I _finish my homework first. 2.I_ get up early tomorrow, because I have a meeting.,must,must,3. The book _ be returned before Saturday. 4. You _give up smoking at once. Its bad for your health. 5. _ I finish the work now? 6. Look at the ground. Its very wet. It _ have rained last night.,must,must,Must,must