资源描述：
《Section A Grammer focus 4a--4c》由会员上传分享，免费在线阅读，更多相关内容在应用文档-天天文库。
1、SectionA3(GrammarFocus-4c)I.Revision1.Checkifyouknowthesephrases.①不同种类的污染②河底③把垃圾扔到河里④在…中起作用⑤在中国南部⑥对……有害⑦在……顶部⑧海洋生态系统2.TranslatethesesentencesintoEnglish.①甚至是河底都满是垃圾。②这个方法不仅残酷还对环境有害。③鲨鱼处于海洋食物链的顶部。④许多人相信鱼翅对健康有好处。II.GrammarFocusPayattentiontothesentences.1)We’retryingtosaveth
2、eearth.2)Theriverusedtobesoclean.3)Theairisbadlypolluted.4)Noscientificstudieshaveshownthatsharkfinsaregoodforhealth.5)Weshouldhelpsavethesharks.1.现在进行时:PresentProgressive定义：表示说话时（瞬间）正在进行的动作，也表示目前或现阶段一直进行的动作。结构:be(am/is/are)+v.-ing标志词：Look,Listen,now,rightnow…e.g.Look!Theb
3、oyiscrying.2.usedtodo与beusedtodoingusedtodosth.表示过去常常做某事,而现在往往不做了,后接动词原形。beusedtodoingsth.表示习惯于做某事。e.g.Iusedtogetupatsixo’clock.Joeisusedtodrinkingacupofcoffeeeverymorning.3.被动语态：Passivevoice定义：表示主语是动作的承受者，即行为动作的对象的一种语态。结构：be+过去分词e.g.Anewschoolwasbuiltlastyear.Ourclassroom
4、iscleanedeveryday.4.现在完成时:PresentPerfect定义：表示动作已经完成,但对现在造成影响;或者表示从过去某一时间开始一直延续到现在并还可能持续下去的动作。结构:has/have+过去分词标志词：already,yet,ever,never,since,for…e.g.Ihaven’tfinishedmyhomeworkyet.5.情态动词1)情态动词本身有一定的词义，表示说话人的情绪、态度或语气，但不能单独作谓语，只能与其他动词构成谓语。常见的有：can(could),may(might),must,need
5、,shall(should),will(would)等。2)情态动词无人称和数的变化,后接动词原形。否定式是在情态动词后面加not。个别情态动词有过去式形式,可用来表达更加客气、委婉的语气。e.g.Kencanclimbupthetresslikeakoala.Tracycouldrideabicyclewhenshewasfiveyearsold.Youmustn’tplaywithfire.Itisdangerous.III.Practice1.Workon4a.Fillintheblankswiththecorrectformsoft
6、heverbsinbrackets.Joe:_____youever______(take)partinanenvironmentalproject?Eric:Yes,Ihave.I______(help)withaClean-UpDaylastyear.Itwas_________(consider)thebiggestclean-upprojectthiscity____ever____(have).Joe:Howmanypeople____(take)part?Eric:I_______(think)morethan1,000peop
7、le______(come)tohelpout.Joe:That’sfantastic!Iguesseveryoneinthiscityis______(try)toimprovetheenvironment.Eric:Yes,wecan’taffordto____(wait)anylongertotakeaction!Learnsomenewwordsandexpressions.2.Workon4b.Fillintheblankswiththeappropriatemodalverbsfromthebox.Thewordsare:can
8、,would,could,haveto,should,must,may/mightPeople__________thinkthatbigthings______bedoneto
