备考指导#考研究生倒计时#阅读模拟练习[3]

Scientistshaveknownsince1952thatDNAisthebasicstuffofheredity.They'veknownitschemicalstructuresince1953.TheyknowthathumanDNAactslikeabiologicalcomputerprogramsome3billionbitslongthatspellsouttheinstructionsformakingproteins ，thebasicbuildingblocksoflife.

Buteverythingthegeneticengineershaveaccomplishedduringthepasthalf-centuryisjustapreambletotheworkthatCollinsandAndersonandlegionsofcolleaguesaredoingnow.CollinsleadstheHumanGenomeProject
，a15-yearefforttodrawthefirstdetailedmapofeverynookandcrannyandgeneinhumanDNA.Anderson，whopioneeredthefirstsuccessfulhumangene-therapyoperations ，isleadingthecampaigntoputinformationaboutDNAtouseasquicklyaspossibleinthetreatmentandpreventionofhumandiseases.

Whattheyandotherresearchersareplottingisnothinglessthanabiomedicalrevolution.LikeSiliconValleypiratesreverse-engineeringacomputerchiptostealacompetitor'ssecrets
，geneticengineersaredecodinglife'smolecularsecretsandtryingtousethatknowledgetoreversethenaturalcourseofdisease.DNAintheirhandshasbecomebothablueprintandadrug，apharmacologicalsubstanceofextraordinarypotencythatcantreatnotjustsymptomsorthediseasesthatcausethembutalsotheimperfectionsinDNAthatmakepeoplesusceptibletoadisease.

Andthat'sjustthebeginning.Forallthefeveredworkbeingdone ，however，scienceisstillfarawayfromtheBraveNewWorldvisionofengineeringaperfecthuman—orevenaperfecttomato.Muchmoreresearchisneededbeforegenetherapybecomescommonplace
，andmanydiseaseswilltakedecadestoconquer，iftheycanbeconqueredatall.

Intheshortrun ，themostpracticalwaytousethenewtechnologywillbeingeneticscreening.DoctorswillbeabletodetectallsortsofflawsinDNAlongbeforetheycanbefixed.Insomecasestheknowledgemayleadtotreatmentsthatdelaytheonsetofthediseaseorsoftenitseffects.Someonewithageneticpredispositiontoheartdisease
，forexample，couldfollowalow-fatdiet.Andifscientistsdeterminethatavitalproteinismissingbecausethegenethatwassupposedtomakeitisdefective ，theymightbeabletogivethepatientanartificialversionoftheprotein.Butinotherinstances
，almostnothingcanbedonetostoptheravagesbroughtonbygeneticmutations.(409words)

1.ItcanbeinferredfromthetextthatCollinsandAndersonandlegionsofcolleagues_____.

[A]knowthathumanDNAactslikeabiologicalcomputerprogram

[B]havefoundthebasicbuildingblocksoflife

[C]haveaccomplishedsomegeneticdiscoveryduringthepasthalf-century

[D]aremakingabreakthroughinDNA

2.CollinsandAndersonarecitedinthetexttoindicateallthefollowingEXCEPTthat______.

[A]time-consumingeffortisneededtoaccomplishthedetailedmapofinhumanDNA

[B]humangene-therapyoperationsmaybeappliedtothepatients

[C]gene-therapynowisalreadygenerallyusedtothetreatmentandpreventionofhumandiseases

[D]informationaboutDNAmaybeusedinthetreatmentandpreventionofhumandiseases

3.Theword“pirate ”(line2，paragraph3)means______.

[A]onewhorobsatseaorplundersthelandfromthesea

[B]onewhomakesuseoforreproducestheworkofanotherwithoutauthorization

[C]totake(something)bypiracy

[D]tomakeuseoforreproduce(another'swork)withoutauthorization

4.Wecandrawaconclusionfromthetextthat_____.

[A]engineeringaperfecthumanisnotfeasibleforthetimebeing

[B]it‘simpossibleforscientiststoengineeraperfecttomato

[C]manydiseaseswillneverbeconqueredbyhumanbeings

[D]doctorswillbeabletocureallsortsofflawsinDNAinthelongrun

5.Thebesttitleforthetextmaybe______.

[A]DNAandHeredity

[B]TheGeneticRevolution

[C]ABiomedicalRevolution

[D]HowtoApplyGeneticTechnology