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1、I’venevermetahumanworthcloning,”sayscloningexpertMark阅读理解答案 I’venevermetahumanworthcloning,”sayscloningexpertMarkWesthusinfromhislabatTexasA&MUniversity.“It’sastupidendeavor.” That’saninterestingchoiceofadjective,comingfromamanwhohasspentmillionsofdollarst
2、ryingtoclonea13-year-olddognamedMissy.Sofar,heandhisteamhavenotsucceeded,thoughtheyhaveclonedtwocowsandacat. TheyjustmightsucceedincloningMissysoon—orperhapsnotforanotherfiveyears. Westhusin’sexperiencewithcloninganimalsleaveshimupsetbyallthistalkofhumancl
3、oning.InthreeyearsofworkontheMissyproject,usinghundredsuponhundredsofdog’seggs,theA&MteamhasproducedonlyadozenorsoembryoscarryingMissy’sDNA.Nonehavesurvivedthetransfertoasurrogate（代孕的）mother.Thewastageofeggsandthemanyspontaneouslyaborted(流产，发育不全)fetuses（胎）ma
4、ybeacceptablewhenyou’redealingwithcatsorbulls,heargues,butnotwithhumans.“Cloningisincrediblyinefficient,anda lsodangerous,”hesays. Evenso,dogcloningisacommercialopportunity,withaniceresearchpayoff.EversinceDollythesheepwasclonedin1996,Westhusin’sphonehas
5、beenringingwithpeoplecallinginhopesofduplicatingtheircatsanddogs,cattleandhorses.“Alotofpeoplewanttoclonepets,especiallyifthepriceisright,”saysWesthusin.CostisnoobstacleforMissy’smysteriousbillionaireowner;he’sputup$millionsofartofundA&M’sresearch. Contrary
6、tosomemediareports,Missyisnotdead.TheownerwantsatwintocarryonMissy’sfinequalitiesaftershedoesdie.Theprototype（原型；雏形）is,byallaccounts,athletic,good-naturedandsuper-smart.Missy’smasterdoesnotexpectanexactcopyofher.Heknowsherclonemaynothavehertemperament（气质、性情）
7、.Inastatementofpurpose,Missy’sownerandtheA&Mteamsaytheyare“bothlookingforwardtostudyingthewaysthatherclonesdifferfromMissy.” Besidescloningagreatdog,theproje ctmaycontributeinsightintotheoldquestionofnaturevs.nurture.Itcouldalsoleadtothecloningofspecialr
8、escuedogsandmanyendangeredanimals. However,Westhusiniscautiousabouthiswork.Heknowsthatevenifhegetsadogpregnant,theoffspring,shouldtheysurvive,willfacetheproblemsshownatbirthbyotherclonedanimals
