【托福寫作范文】托福綜合寫作優(yōu)秀作文練習(xí)題-環(huán)保材料乙醇在托福備考的過程中，綜合寫作往往對(duì)于很多學(xué)生來說都會(huì)是一大難點(diǎn)，因?yàn)槠渲袇R集了聽、寫、讀等各個(gè)方面的內(nèi)容要素，想要讓其達(dá)到高分并不是件很難的事情。那么，在以下的內(nèi)容中，我們就為大家?guī)硪恍╆P(guān)于托福綜合寫作的練習(xí)材料，希望能為大家的托福備考帶來幫助。托福綜合寫作閱讀材料：Ethanolfuel,madefromplantssuchascornandsugarcane,hasbeenadvocatedbysomepeopleasanalternativetogasolineintheUnitedStates.However,manycriticsarguethatethanolisnotagoodreplacementforgasolineforseveralreasons.乙醇燃料是從玉米或者甘蔗之類的植物中提取的。在美國，一些人提倡使用乙醇燃料來代替汽油。然而，很多評(píng)論家認(rèn)為一些原因使得乙醇燃料不是良好的汽油替代品。First,theincreaseduseofethanolfuelwouldnothelptosolveoneofthebiggestenvironmentalproblemscausedbygasolineuse:globalwarming.Likegasoline,ethanolreleasescarbondioxideintotheatmospherewhenitisburnedforfuel,andcarbondioxideisagreenhousegas:ithelpstrapheatintheatmosphere.Thus,ethanoloffersnoenvironmentaladvantageovergasoline.首先，使用汽油帶來的最大的問題之一是全球變暖，而對(duì)于乙醇燃料使用的增加并不能解決這個(gè)問題。同汽油一樣，乙醇燃燒后向大氣釋放二氧化碳，而二氧化碳是溫室氣體。它會(huì)保持大氣層內(nèi)的溫度。因而，相對(duì)于汽油來說，乙醇并沒有環(huán)保優(yōu)勢(shì)。Second,theproductionofsignificantamountsofethanolwoulddramaticallyreducetheamountofplantsavailableforusesotherthanfuel.Forexample,muchofthecornnowgrownintheUnitedStatesisusedtofeedfarmanimalssuchascowsandchickens.Itisestimatedthatifethanolwereusedtosatisfyjust10percentofthefuelneedsintheUnitedStates,morethan60percentofthecornEthanolactuallyisagoodalternativetogasolinealthoughyoujustreadthreereasonswhyitisnotagoodalternative.Notoneofthesethreereasonsisconvincing.雖然閱讀部分說乙醇燃料不是汽油很好的代替品，但是事實(shí)上是可以很好代替汽油的。閱讀部分給出的三個(gè)理由都是沒有說服力的。First,theincreaseduseofethanolwillnotaddtoglobalwarming.Itistruethatwhenethanolisburned,itreleasescarbondioxideintotheatmosphere.Butasyouread,ethanolwasoftenmadefromplantssuchascorn.Well,theprocessofgrowingtheplantscounteractsthisreleaseofcarbondioxide.Letmeexplain.Everygrowingplantabsorbscarbondioxidefromtheairasapartofitsnutrition.So,growingplantsforethanolproductionactuallyremovescarbondioxidefromtheatmosphere.首先，提高對(duì)乙醇燃料的使用不會(huì)導(dǎo)致全球變暖。誠然，燃燒乙醇燃料的時(shí)候是會(huì)向空氣中排放二氧化碳。但是，就像在閱讀部分看到的，通常來說乙醇燃料是由玉米之類的作物制造的。恩，這些作物生長的過程中可以抵消掉乙醇燃料燃燒所釋放的二氧化碳的。我來解釋一下。所有作物在生長的過程中都會(huì)吸收空氣中的二氧化碳作為養(yǎng)料。所以，為制造乙醇燃料而種植的作物事實(shí)上可以吸收乙醇燃料排放到空氣中的二氧化碳。Second,largescaleproductionofethanoldoesnothavetoreducethesourceoffoodforanimals.Thatisbecausewecanproduceethanolusingcellulose.Celluloseisthemaincomponentofplants’cellwalls,andyoufindmostcelluloseinthosepartsofplantsthatarenoteatenbyanimals.So,sincewecanproduceethanolfromtheplantpartsthatarenoteaten,theamountofanimalsfeedthatisavailablewillnotbereduced.第二，大量生產(chǎn)乙醇燃料不會(huì)減少畜牧業(yè)的飼料供應(yīng)。這是因?yàn)槲覀冇美w維素制造乙醇燃料。纖維素是植物細(xì)胞壁的主要組成成分，而且多數(shù)作物富含纖維素的部分都是家畜不食用的。所以，鑒于我們是使用家畜不食用的部分來制造乙醇燃料的，那么家畜可使用的飼料不會(huì)減少。Third,inthefuture,ethanolwillbeabletocompetewithgasolineintermofprice.Itistruethatthegovernmentsubsidiesmakeupethanolischeaperthanitwouldnormallybe,butthissupportwouldnotalwaysbeneeded.Onceenoughpeoplestartbuyingethanol,ethanolproducerswillincreasetheirproductionofethanol.Generally,increasedproductionofaproductleadstoadropinitsprice,sothepriceofethanolwillgodownasmoreofitbecomesavailable.Studyshowsthatifethanolproductioncouldbethreetimesgreaterthanitisnow,thecostofproducingaunitofethanolwoulddropbyfortypercent.第三，在未來，乙醇燃料可以在價(jià)格上同汽油競爭的。確實(shí)，現(xiàn)在政府的補(bǔ)貼政策使得乙醇燃料的價(jià)格比實(shí)際要低，但是這樣的補(bǔ)貼政策不需要一直存在。一點(diǎn)有足夠多的人購買乙醇燃料，那么乙醇燃料的制造商將會(huì)更多地生產(chǎn)。一般來說，對(duì)某產(chǎn)品的生產(chǎn)增多會(huì)導(dǎo)致價(jià)格下降，所以當(dāng)乙醇燃料的產(chǎn)量增加之后，價(jià)格也會(huì)隨之下降。研究表明如果乙醇燃料產(chǎn)品的產(chǎn)量增加三倍，那么每個(gè)單位乙醇燃料的價(jià)格將會(huì)下降40%。托福綜合寫作聽力筆記：Mainpoint:三個(gè)理由都沒有說服力Subpointone:乙醇燃料雖然會(huì)產(chǎn)生二氧化碳，但是制造乙醇燃料的作物在生長的過程中會(huì)吸收二氧化碳Subpointtwo:生產(chǎn)乙醇燃料使用的是動(dòng)物不食用的部分，不會(huì)影響動(dòng)物的飼料供應(yīng)Subpointthree:乙醇燃料的價(jià)格會(huì)在使用量增大后下降托福綜合寫作范文(僅供參考)：Theprofessorinthelecturedefinitelybelievesthatethanolisagoodalternativeofthegasoline.Hisviewpointisdefinitelyoppositetothestatementsmadeinthereadingpassage.Actually,hefindsthestatementsmadebythereadingpassageunconvincing.Ononehand,theprofessorpointsoutthatburningethanolwillnotaddtoglobalwarmingasthestatementmentionedinthereadingpassage.Althoughburningethanolwillreleasecarbondioxideintotheatmosphere,thegrowingprocesswillcounteracttheeffortbyabsorbingcarbondioxideintheair.Therefore,theprofessorfindsthefirststatementinthereadingpassageunconvincing.Ontheotherhand,theprofessorindicatesthatproducingethanolwillnotreducetheamountoffoodforanimals.Infact,theprofessorsayswecanproduceethanolbyusingcellule,whichwillnotbeeatenbyanimals.Therefore,theamountofplantsforotherusewillnotdecreaseasthereadingpassagementions.What’smore,theprofessorcountersthatethanolwillcompetewithgasolineintermsofprice.