1、Unit7Protect the EarthIntroduceI can use _ to _.We should _.We should not _.Words“use+名词+to+动词原形”意思是用某物做某种东西。to后接动词原形。常用短语：protect the earth 保护地球eg：She always uses too much water to clean things.她总是用太多的水来清洗东西。小练习：In the past,we often _(use)wood to make fire.useduse toWords(1)used to表示过去常常做某事。(2)be u
2、sed to+doing：“习惯于”,to是介词,后需加名词或动名词。eg：I used to play football after school。过去我常常在放学后踢球。Use to扩展eg：Sarah is used to taking a walk。Sarah习惯于散步了。WordsShould“应该”,后接动词原形,是较委婉地建议某人做某事。当表示较委婉的拒绝某人做某事时：用其否定形式“shouldnt+动词原形”。eg：We should finish our homework every day.我们每天都应该完成家庭作业。小练习：（）Water is useful,we _ r
3、euse and save it.A.should B.shouldnt C.will Ashould/d/Dialogues Group work：Write more sentences with learned sentences and report in class.Expand(1)(表示能力)能;会 can作情态动词用法eg：She can drive，but she cant ride a bicycle.他能开车,但是不会骑自行车。(2)(表示可能、许可)能够;可以eg：You cant park your car in this street.你不可以在这条街上停车。Exp
4、andcould/be able to 区别could表示“原来具备某种能力,现在没有这种能力了”。但was/were able to则表示过去成功地做成了某事。eg：I could swim all the way across the lake，but I cant now.我原来能游过这个湖,但现在不能了。The fire spread through the hotel very quickly but everyone was able to get out.大火很快蔓延了整个旅馆,但全体人员都脱离了危险。SummaryUse toshouldExercise()1.The oil
5、is .A.use B.reuse C.useful()2.To keep the air clean,dont to work every day.A.walk B.run C.driveCCExercise()3.We often use to clean things.A.coal B.oil C.water()4.There some paper on the desk.A.has B.is C.areCBExercise()5.People cut down trees every day.A.lot of B.many C.much()6.We can use paper a to
6、y plane.A.make B.making C.to makeBCExercise()7.There are plastic bags on the ground.A.too much B.too many C.so much()8.To protect the Earth,we should use .A.plastic bags B.plastic bottle C.glass bottleBCHomeworkCollect more examples of environmental damage,write a small report，report showing in the class.
