2）Let's not +动词原形 Let's not say anything about it.

　　Don't let +第三人称代词或名词+动词原形 Don't let them play in the street.

　3）No+名词或动名词（相当于否定的祈使句）No photos No smoking=Don't smoke .

　　即学即练 1) _______( not stand) too close to the animals. It's too dangerous.

　2). _______ late next time.A. Be not B. Don't be C. Aren't D. Not to be

　3). ________late for class! A. Don't B. Not be C. Don't be

　4).Let's run in the hallways.（改为否定句）_____ _____ in the hallways.

2. 情态动词have to.与 must的用法：

1) have to.结构:主语+have/has to+动词原形+其他 否定形式:主语+don't/doesn't have to+动词原形+其他 疑问句：Do /Does +主语+have to +动词原形+其他

即学即练She has to do her homework first. (否定句)She _____ ____ _____ do her homework.

2）must"必须，应该"，否定句中用mustn't，以must开头的一般疑问句，肯定回答must否定回答用needn't。 --Must I go there on foot? ---No, you needn't. You mustn't park your car here.

3）区别have to与must

have t"不得不"有时态、人称和数的变化，指外部环境有要求，多表达客观要求。

Must"必须"无时态、人称和数的变化，多表达主动的意思，出于本人自觉。或表示有做某一个动作的必要和义务，

即学即练1）I do my homework now. 2）It's too late . I ______ leave now.

　3）.Mr Smith ______ look after his son and daughter because his wife is ill.

　　　　　　　　　　　　　　　　　快乐检测

一．单词拼写

1.You'd better not break the r________. 2. ________ (not fight ) with each other in the classroom.

3.We can eat in the d_________ hall every da 4.No _________(talk) in class!

5.Grace is wearing the school u_________ today.

6.The girl often comes back early on s_________ nights.

7. _________(read) in the sun is bad for your eyes.

二 .单项选择

( ) 16. _____ your homework after school. A. Doing B. To do C. Do

( ) 17. Don't arrive late___school. A. loud B. loudly C .aloud

( ) 18. Can we ____in the hallways? A. to eat B. eat C. eating

( )11.I have __ rules in my home. We have ___ homework to do today.

　　A. too many, too much B. too much , many too

　　C. too many, much too D. much too, many too

( ) 20. ____ sleeping in class. A. Can't B. Don't C.No

( ) 21. Please ____ play volleyball here. A. please B. do C. don't

( ) 24. --- ____Tom___go to bed by ten? A. Do; has to B .Does; have to C. Does; has to

( )21. Don't _______ in the hallways at school. A. smile B. fight or run C. wear a uniform

( )22. -Do I have to make dinner? A.Yes,you do B.No, you can't C. No,I don't D. Yes,I do

( )23. ------Don't eat in class,Bill. -----____A. Yes,l do B. No.I don't C. Sorry,l won't ( )24. You must come here_________.A.in time B. on time C. at time D. sometimes

( )30. We must ____________the school rules. A. follow B. take C. Bring D.write

( )31. Her mother is very strict__________her. A. at B. on C. in D. with

( )32. Do you have to _________every morning?

A. make a bed B. make your bed C. make bed D. make you bed

( )34. We have lots of fun ________games.A. play B. to play C. playing D. plays

( )25. He wants ____music to relax himself.A. to listen to B. listen to C. listen D. to listen