第四課時Grammar——不定式作主語TeachingobjectivesLearnthegrammaticalcontentoftheinfinitiveassubjectandcanuseitskillfully【課前預習】[合作探究]閱讀下列句子，體會動詞不定式的用法。Toseeistobelieve.百聞不如一見。Itisinterestingtoplaywithsnowinwinter.冬季里玩雪是很有趣的。It’simportantforhumanbeingstokeepthebalanceofnature.保持自然平衡對人類來說很重要。[自主發(fā)現(xiàn)]不定式是非謂語動詞的一種，沒有和的變化，在句中可以作(有名詞和代詞的作用)，通常表示、行為?！菊n內(nèi)探究】一、用法不定式位于句首TostudyEnglishwellisnoteasy.學好英語不容易。it作形式主語，把不定式(短語)置于句末。為了避免頭重腳輕，可用it作形式主語，把不定式(真正主語)放到句子后面。ItwouldbeagreathonorformetoinviteyoutocometoChina.邀請你來中國對我來說是一件非常榮幸的事。Asweallknow，itisgoodforyourhealthtostopsmoking.眾所周知，戒煙益于健康。二、動名詞和不定式作主語的區(qū)別一般來說，不定式作主語表示一次性的、具體的動作，而動名詞作主語表示一種抽象的和泛指的動作。Tolieiswrong.說謊是錯誤的。(對于說謊者是誰，說話人心中是有所指的)Swimmingisgoodexercise.游泳是一項很好的鍛煉。(指游泳這項運動)鞏固練習：①Ittakesabouttenminutes.步行去銀行大約用十分鐘時間。②It’simportantforyoul.對你們來說學好外語非常重要。③It’sverykind.你這樣說真是太好了。④Itmustbegreatfun.乘宇宙飛船飛往月球一定很有趣。⑤hasn’tbeendecidedyet.什么時候開會還沒有定下來呢。注意：不定式與疑問詞how,what，when，where,which等連用構(gòu)成不定式短語，也可作主語。Howtousethecomputerisaquestion.如何使用計算機是個問題?！菊n后鞏固】Ⅰ.用括號內(nèi)所給動詞的適當形式填空1.Itiswise(take)suchgiftswithgratitude.2.Hewillfinditiseasy(make)friendsinthiscity.3.(get)therebybikewilltakeushalfanhour.4.Itisanoffence(drop)litterinthestreet.5.When(leave)forLondonhasnotbeendecidedyet.6.It’snecessaryforyou(lock)thecarwhenyoudonotuseit.7.Wecan’tafford________(live)insuchabighouse.8.Themanexpectshiswife________(bring)himbreakfastinbedatweekends.9.Afraidof________(bite)bysnakes,theboywasafraid________(touch)them.10.JamesWattisknown________(invent)thesteamengine.11.Thebookwassaid________(translate)intoGermanin1946.12.Themeeting________(hold)tomorrowisofgreatimportance.13.Aquarrelseems________(breakout)betweenthetwowomenandtheyarestillglaringateachothernow.Ⅱ.補全句子isagoodhabit.每天讀書是個好習慣。isnice.和他們交朋友真是令人愉快。todomeafavour.你能幫助我真是太好了。doesgoodtoyourhealth.晚飯后散步對健康有好處。5.Itisimpossibleforlosttime.彌補失去的時間是不可能的。6.Itisdifficultforusinaquarterofanhour.Ⅲ語法填空Mikedrovetoaremotebordertownalone.Hedidn’tstopthecar1.________(take)abreakalthoughhewasfeelingtired.Asaresult,atrafficaccidentoccurred,whichcausedhim2.________(trap)insidethecar.Fortunatelyagirlwhohappenedtopassbyvolunteered

3.________(save)him,only4.________(find)Mikewascompletelylockedinthecar.

Aftercallinganambulance,shemanaged5.________(give)himfirstaid,usingthemethodshehadlearnedatschool.Soon,Mikewasrushedtohospitalinanambulance.Ittookhimthreemonths6.________(recover)fromhisinjuries.

ThegirlnamedMaryfeltpleased7.________(do)suchagreatthing,thoughsherealizedthecarmayhaveexploded.Wheninterviewed,shesaid,“I’vealsometwithatrafficaccident.Akindpasser-bysavedmylifebuthewaskilled.Iwastheonlyone8.________(survive)thecrash.Themanwassaid9.________(work)onthe