新托福TPO 21综合写作详细解析：基因改良

第2页/总页数5页
新托福TPO21综合写作详细解析:基因改良
阅读材料:
Geneticmodification,aprocessudtochangeanorganism’sgenesandhenceitscharacteristics,isnotbeingudtoimprovetrees.Throughgeneticmodification,itispossibletocreatetreesthatproducemorefruit,growfaster,orwithstandadverconditions.Plantinggeneticallymodifiedtreesonalargescalepromistobringanumberofbenefits.
基因改良是通过改变有机体的基因,进而改变其性状的过程。目前还没有用来改良树木。通过基因改良,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,种植基因改良树木可以带来诸多益处。
First,geneticallymodifiedtreesaredesignedtobehardierthannaturetrees;thatit,theyaremorelikelytosurvivethantheirunmodifiedcounterparts.InHawaii,forexample,anewpestresistantspeciesofpapayatreehasbeendevelopedinrespontoringspotvirusinfectionsthathaverepeatedlydamagedthenativepapayatreepopulation.Plantingthegeneticallymodifiedpapayashaslargelyputanendtotheringspotproblem.
首先,基因改良树木设计得比天然树木更能承受不良环境。也就是说,相对于它们没有改良的同类,它们更易存活。比如,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。种植这种基因改良的番木瓜可以很大程度上解决环斑病毒的问题。
Moreover,geneticallymodifiedtreespromitobringanumberofeconomicbenefitstothowhogrowthem.Geneticallymodifiedtreestendtogrowfaster,givegreateryields–offood,fruit,orotherproducts–andbehardier.Thisallowstreefarmerstogetfasterandgreaterreturnsontheirfarminginvestmentandsaveonpesticidesaswell.
第3页/总页数5页
而且,基因改良的树木据信可以给种植者带来巨大的经济利益。基因改良的树木基因改良更快。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。
Finally,theuofgeneticallymodifiedtreescanpreventoverexploitationofwildtrees.Becauofthegrowingdemandforfirewoodorbuildingtimber,manyforestsaroundtheworldarebeingcutdownfasterthantheycanbereplaced.Introducinggeneticallymodifiedtrees–designedforfastgrowthandhighyieldingivengeographicconditions–wouldsatisfythedemandforwoodinmanyofthoareasandsavetheendangerednativetrees,whichoftenincludeuniqueorrarespecies.
最后,种植基因改良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、产量更大的改良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。
阅读部分需要提取的观点是:
Mainpoint:基因改良树木优点很多
Subpoint1:可以抵御病虫害
Subpoint2:可以提高农民的收入
Subpoint3:可以保护天然森林
听力材料:
Sure,thereisbenefittoplantinggeneticallymodifiedtrees,butarethetreesreallyasgreatastheyfirstsound?Whenyouexaminethesubjectscloly,therearesomeriousproblemsandcausassociatedwiththeusingofgeneticmodifiedtrees.
当然,种植基因改良树木是有好处的,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,就会发现基因改良树木会带来一些严重的问题。
First,geneticallymodifiedtreesmayberesistanttooneparticularcondition,butitdoesn’tnecessarilyensuretheirsurvival.Youe:atypicalnonmodifiedtreepopulationisgeneticallydiver.Thatmeansthatformostthreateningconditions,forclimate,incts,andpests,whatever,therewillbeatleastsomeindividualtreesofanygivenspeciestreethatareresistant.So,evenifthemostofonekindoftreewerekilled,thofewresistantoneswillsurviveandensurethesurvivalofthatspeciesoftree.But,geneticallymodifiedtreesaregeneticallymuchmoreuniform,soifthereissuppodtoanenvironmentalchallengetheyhavenotbeendesignedfor,theywillalldie.So,iftheclimatechangesornewpestengagesin,thegeneticallymodifiedtreeswilllikelybecompletelywaggedout.
第3页/总页数5页