1、1Unit 3 Safety1. Look at this yellow star, Brian and Jenny! 布莱恩、詹妮，看这颗黄色的星星！2. Let me get the ladder for you.让我给你拿把梯子。3. Dont stand on chairs. 不要站在椅子上。4. Be careful with scissors and knives!小心剪刀和刀子！5. Never smoke because of much pressure!永远不要因为压力大而吸烟！1. 定义祈使句是英语中的基本句型之一，用来表达建议、命令、请求、警告、劝告、禁止等语气。祈使句的
2、主语一般为第_人称，通常可以_。为了使语气更加客气或缓和，可在句前或句末加上_一词。2. 构成(1)祈使句的肯定形式一般以_动词或_动词原形开始，也可以以动词let 开始。(2)祈使句的否定形式一般在句首加_或_。(3)以 let 开头的祈使句：肯定句：Let him come in.否定句：Dont let him come in.或 Let him not come in.(4)有些祈使句可用 No 开头，表示禁止。No smoking, please. 请不要吸烟。No photos! 禁止拍照！3. 拓展(1)祈使句的反意疑问句祈使句的反意疑问句，若陈述部分是否定句，则附加问句只能用
3、will you。若陈述部分是肯定句，附加问句既可用 will you，也可用 wont you。lets 开头的祈使句用于提出建议，包括对方，其附加问句用 shall we。let us 开头的祈使句表示征求对方许可，其附加问句用 will you。Dont do that again, will you?Go with me, will you/wont you?Lets go, shall we?2Let us take an exam, will you?(2)祈使句用于两个重要句型“祈使句and表结果的陈述句”用来叙述肯定的条件。“祈使句or表结果的陈述句”用来叙述否定的条件。注意
4、这两个句型都可以改写为 if 引导的条件状语从句。Work hard, and you will pass the exam.(If you work hard, you will pass the exam.)Work hard, or you will not pass the exam.(If you dont work hard, you will not pass the exam.) .单项选择( )1. 2017白银 Boys and girls，_ learning and have fun.Akeep Bto keep Ckeeping Dkept( )2. _careful
5、ly, please! Look at the road sign. There is a school ahead.ADrive BTo driveCDriving DDrives( )3. _ patient with him, please. He is only three years old. ADont BBe CIs DDoes ( )4. 2017渝北_throwing those stones, please.AStop BStops CStopping DStopped( )5. 2017安徽 Hold your dream，_ you might regret some
6、day.Aand Bor Cbut Dso( )6.2017滨州I want to be a teacher when I grow up.Work hard，_ your dream will come true.Aor Bbut Cthough Dand. 按要求完成下列各题1. 2017达州 This warning sign tells us not to pick flowers. (保持句意基本不变)This warning sign says “_ _ flowers”2. 2016天水 Tell him the truth at once, or he will be angr
7、y. (改为主从复合句)_ _ dont tell him the truth at once, he will be angry.3. 2017天水 Let us go hiking, _？ (完成反意疑问句)4. You should be relaxed. (改为祈使句)_ _， please.5. Dont park here. (改为同义句)_ _！教师详解详析【语法探究】1. 二； 省略； please 2. (1)实义； be (2)dont; never 【实战演练】.16 AABABD .1. Dont pick/No picking 2. If you3. will you 4. Be relaxed 5. No parking
