Unit 4 Don't eat in class.【知识点精讲精练】-2021-2022学年七年级英语下册同步知识点一网打尽（人教版）

Unit 4 Don't eat in class. Grammar 目录 语法 祈使句 1 语法 have to/must 2 课后练习 2 语法 祈使句 祈使句：用来发出命令或指示，提出要求、建议、劝告等的句子。其有四种类型： ►1.do型：实义动词+其他，否定式为Don’t+实义动词+其他 例句：Listen to me, please. Don’t believe him! ►2.be型：Be+表语+其他成分，否定式为Don’t be +其他成分 例句：Be quiet, please. Don’t be careless! ►3.let型：Let+sb+动词原形，否定式为Don’t let sb. do或Let+sb+not+动词原形+其他。 例如：Let’s go. Let her not do that. Don’t let Jim do that. ►4.“No+名词/动词-ing”，表示公共场合的警示语，为祈使句的一种省略形式。 例句：No parking. No photos! 禁止拍照！ 【练习29】（单项选择）—_______ late for school again. —Sorry, I won't. A．Not be B．Don't be C．Not D．Don't 【练习30】（完成句子）不要听音乐！请安静！ Don't listen to music! Please_______ _______ ! 【练习31】（单项选择）_______in the school library. A．Not talk or eat B．Not talking or eating C．Don't talk or eat D．Don't talking or eating 【练习32】（单词变形）_______(not eat) in class. 【练习33】（单词变形）Look at the sign: "No_______!" （talk） 语法 have to/must ►1.must.表示“必须”，强调主观上意识到必须做某事 【注意】mustn’t表示“不准；不许”，表示语气较为强烈的禁止. 例句：You mus to obey the rules.你们必须遵守这些规定。 You mustn’t touch anything.你们不许摸任何东西。 ►2.have to.表示“不得不；必须”，含有“被迫；强迫”之意，强调客观。 【注意】变疑问句或否定句时要借助于助动词do 例句：We have to wear school uniforms on Mondays. Do you have to stay at home today? 【练习34】（完成句子）饭后你必须洗餐具吗？ Do you _______ _______ do the dishes after meals? 【练习35】（单词变形）Sometimes Jim has to _______ (make) breakfast for himself. 【练习36】（完成句子）吉姆今天必须完成家庭作业。 Jim _______ _______ his homework today. 【练习37】（单词变形）She must _______ (play) the violin for an hour in the club on weekends. 【练习38】（单项选择）—Can you join us for dinner tonight? —Sorry, I’m afraid not. I _______ look after my sister. A．can’t B．can C．have to D．has to 课后练习 1、用所给单词的适当形式填空。 1.Please _______ (not support) the young girl. She is impolite. 2._______(not run) in the hallways. 3.She must _______ (play) the violin for an hour in the club on weekends. 4.Do you have to _______ (wear) school uniforms every day? 5._______ (not draw) on the wall. 6._______ (not be) late again. 7._______ (not listen) to music in class, Jen