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托福TPO21综合写作范文及材料 TPO21综合写作阅读材料认为种植基因改进树木可以带来诸多益处听力材料就个观点进行了逐一反驳下面是的托福TPO21综合写作范文和听力原文,欢送阅读! Thereadingandlisteningmaterialshaveaconflictofopinionsaboutgeicmodification.Thewriterbelievesthatitisbeneficialtothesociety,whichiscontradictedbythefollowinglecture. Firstly,thewriterclaimsthatgeicallymodifiedtreesaremorelikelytosurvivesinceitishardierthanunmodifiedones.However,thespeakercastsdoubtonthisopinionbysayingthatnaturaltreestendtobegeicallydiverse,sotherewillalwaysbesomeresistantkindsthatgettosurvivewhenexposedtoanenvironmentalchallenge.Geicallymodifiedtrees,ontheotherhand,areuniformingenes,whichmeanstheywouldalldieiffacedwithachallengethattheyarenotdesignedfor. Secondly,theauthorarguesthatgeicallymodifiedtreesaremoreprofitabletofarmers,whilethelectureviewsthisissuefromanoppositeangle.Aordingtoher,theseedsofmodifiedtreescostalotandbylaw,farmershavetopaythepanyeverytimetheyplant. Thirdly,thepassagestatesthatgeicallymodifiedtreesmakeitnolongernecessarytooverexploitwildtrees.Bycontrast,inaordancewiththeprofessor,thisclaimdoesnotholdwater.Itisbecausemodifiedtreestendtogrowmoreaggressivelyandwouldoutpetenativetreesfornaturalresourceslikesunlight,waterandsoilnutrition.Asaresult,modifiedtreeswouldactuallywipeoutthenativetreesplantedaroundthem. Geicmodificationaprocessusedtochangeanorganism’sgenesandhenceitscharacteristicsisnotbeingusedtoimprovetrees.Throughgeicmodificationitispossibletocreatetreesthatproducemorefruitgrowfasterorwithstandadverseconditions.Plantinggeicallymodifiedtreesonalargescalepromisestobringanumberofbenefits. 基因改进是通过改变有机体的基因,进而改变其性状的过程目前还没有用来改进树木通过基因改进,可能创造出具有产量高、生长快、抗逆强特点的树木很大程度上,种植基因改进树木可以带来诸多益处 Firstgeicallymodifiedtreesaredesignedtobehardierthannaturetrees;thatittheyaremorelikelytosurvivethantheirunmodifiedcounterparts.InHawaiiforexampleanewpest-resistantspeciesofpapayatreehasbeendevelopedinresponsetoring-spotvirusinfectionsthathaverepeatedlydamagedthenativepapaya-treepopulation.Plantingthegeicallymodifiedpapayashaslargelyputanendtothering-spotproblem. 首先,基因改进树木设计得比天然树木更能承受不良环境也就是说,相对于它们没有改进的同类,它们更易存活比方,在夏威夷有一种新的抗虫害的番木瓜树这种树可以抵抗环斑病毒的感染,而正是这种环斑病毒常常会降低当地番木瓜树的数量种植这种基因改进的番木瓜可以很大程度上解决环斑病毒的问题 点击下载,TPO1—24综合写作解析阅读+听力+范文+答案汇总 Moreovergeicallymodifiedtreespromisetobringanumberofeconomicbenefitstothosewhogrowthem.Geicallymodifiedtreestendtogrowfastergivegreateryields–offoodfruitorotherproducts–andbehardier.Thisallowstreefarmerstogetfasterandgreaterreturnsontheirfarminginvestmentandsaveonpesticidesaswell. 而且,基因改进的树木据信可以给种植者带来巨大的经济利益基因改进的树木基因改进更快同时,产量更高,也就是说可以获得更多的粮食、水果以及其他产品而且,这些树木抗逆性更好这样就能是的弄明可以更多而且更多地收回投资,同时节约杀虫剂的花费 Finallytheuseofgeicallymodifiedtreescanpreventoverexploitationofwildtrees.Becauseofthegrowingdemandforfirewoodorbuildingtimbermanyforestsaroundtheworldarebeingcutdownfasterthantheycanbereplaced.Introducinggeicallymodifiedtrees–designedforfastgrowthandhighyieldingivengeographicconditions–wouldsatisfythedemandforwoodinmanyofthoseareasandsavetheendangerednativetreeswhichoftenincludeuniqueorrarespecies. 最后,种植基因改进树木可以减少对野生树木的过度开发由于对于木柴和建筑木材的越来越大,世界上森林砍伐的速度超过了再生速度引入在相同地里条件下生长更快、产量更大的改进树木可以很多地方对于木材的需求,这样可以保护那些独特而稀少的濒危野生树种 SurethereisbenefittoplantinggeicallymodifiedtreesbutarethesetreesreallyasgreatastheyfirstsoundWhenyouexaminethesubjectscloselytherearesomeseriousproblemsandcausesassociatedwiththeusingofgeicmodifiedtrees. 当然,种植基因改进树木是有好处的,但是真的`有利到可以作为首选作物吗当你仔细审视这些理由的时候,就会发现基因改进树木会带来一些严重的问题 Firstgeicallymodifiedtreesmayberesistanttooneparticularconditionbutitdoesn’tnecessarilyensuretheirsurvival.Yousee:atypicalnon-modifiedtreepopulationisgeicallydiverse.Thatmeansthatformostthreateningconditionsforclimateinsectsandpestswhatevertherewillbeatleastsomeindividualtreesofanygivenspeciestreethatareresistant.Soevenifthemostofonekindoftreewerekilledthosefewresistantoneswillsurviveandensurethesurvivalofthatspeciesoftree.Butgeicallymodifiedtreesaregeicallymuchmoreuniformsoifthereissupposedtoanenvironmentalchallengetheyhavenotbeendesignedfortheywillalldie.Soiftheclimatechangesornewpestengagesinthegeicallymodifiedtreeswilllikelybepletelywaggedout. 首先,基因改进树木可能对某种特定问题有抵抗力,但是这却缺乏以保证它们的生存你看,非基因改进的树木种群是具有基因多样性的这就意味着无论何种树木,即便是在遭遇极端气候灾害或者虫害的情况下,都至少有局部个体对灾害有抵抗能力所以,即便种群中的大多数都死亡了,那么少数有抵抗力的存活下来也能保证这个种群的延续但是对于基因改进树木基因是一直的,所以当他们受到他们基因设计里不能低于的环境挑战时,他们会全部死亡所以,当气候发生变化或者有新的害虫出现,那么基因改进树木就将全部死亡 Thatisthesecondpoint.Therearehiddencausesassociatedwiththegrowinggeicallymodifiedtrees.Youseethepanythatgeicallymodifiedtreecanchargetreefarmersmuchmoreforitsseedsthanunmodifiedtreeseedswouldcost.Alsoafteryou’vegrownthetreeyoucannotjustcollecttheseedsandplantthenewtreeforfree.Bylawyouhavetopaythepanyeverytimeyouplant. 现在说第二点在基因改进树木的生长过程中伴随着一些隐含问题你看,公司都是以高于天然种子很多的价格向农民出售基因改进树木种子的同时,你现在不能再每年收获之后收集种子,然后来年再种了因为根据法律规定,你每年都必须向种子公司支付费用 Andfinallygeicallymodifiedtreesmightactuallycauseevenmoredamagetothelocalwildtrees.Youseegeicallymodifiedtreesoftengrowmoreaggressivelythannaturaltreesdo.Andgeicallymodifiedtreesaretypicallyplantedamongnaturaltrees.Asaresultthegeicallymodifiedtreesoutpetethenativetreesforresources:sunlightsoilnutritionandwater.Eventuallycrowdoutthenaturetrees. 最后,基因改进树木可能会对外乡野生树木造成更多的损害你看,基因改进树木相对于天然树木生长的更为迅猛而且,基因改进树木一般来说跟天然树木是共同生长的那么结果就是,基因改进树木会抢占天然树木的资源,诸如阳光、土壤和水等慢慢地,基因改进树木就会挤走天然树木。