(41~45)Researchershavefoundthatd rugsusedtotr eathumanseizurescandelayaginginwormsbyasmuchas50percent.Theroundwormsusedforthestudyaresimilartohumansintheirmolecularmakeup,raisingthe
possibilitythatthedrugscouldalsoextendthelifespanofhumans。
第41题：“Byfindingaclassofdrugsthatd elaysagingwehavefoundarelationshipbetweenthefunctionofthenervoussystemandagingthatwasnotwellunderstood,”saidKerryKomfeld,ageneticistattheWashingtonUniversitySchoolofMedicineinSt.Louis,Missouri.ThefindingsaredetailedthisweekinthejournalScience。ThediscoverycameoutofthethesisworkbyoneofKomfeld’sgraduatestudents,KimberleyEvason.aboutfouryearsago,EvasonbeganexposinggroupsoftheroundwormCaenorhabditiseleganstocommerciallyavailabledrugstoseeifthedrugswoulddelayagingorpromotelongevity。
A.ButKomfeldsaidscientistswillnotknowabouttheapplicabilityofthedrugsinhumansuntilasimilarstudyisdoneonhumans.“What’sveryencouragingisthatthesedrugsweredevelopedtotr eathumans,andtheyarewellunderstood,becausethey’vebeenusedforalongtime,”hesaid。
B.Laterthescientistsdiscoveredthattworelatedanticonvulsantd rugsalsolengthenedthelivesoftheworms-inthecaseofonedrug,byalmost50percent.“Thiswasabigsurprisetouse,Komfeldsaid.”“Wedidn’tthinkanticonvulsantd rugshadanyparticularrelationshiptoaging.Thatconnectionwascompletelyunexpected.”
C.Roundwormsareapoorsubjectforexperiments,becausetheyarenotlikehumans,eventhoughtheirmoleculesaresimilar.Forexample,theyhavenobones,nordotheyshowemotions,makingitd ifficulttoknowhowexactlyhumansubjectswouldreacttothesedrugsinlargequantities.However,usingthewormsallowsexperimentstobeconductedquickly,becausetheydonotliveforlong。
D.“Somehowtheneuralactivityseemstoregulatetheagingofallofthebodytheskin,musculature,andreproductivetr act,”Kornfeldsaid.“Somehowthenervoussystemcoordinatestheprogressofallthesetissues,evidently,thoughthelifestages.Butwedon’tknowhowitd oesthat.”
E.Thediscoverymayalsoshedlightonthelittle-understoodagingprocess.Sincethedrugsactontheneuromuscularsystemsofbothhumansandworms,thefindingshintatalinkbetweenneuralactivityandaging。
F.Unlikevertebrates,thewormsareidealsubjectsforthestudyofagingbecauseoftheirshortlifespans,whichlastonlyacoupleofweeksinalaboratory.Thewormiswellknowningenetics,andtheworm’sgenomehasbeensequenced。
G.Useofthisdrughasbeenpermittedbylawsince1998andwideruseisnowexpectedasaresultofthestudies.“Wecanclearlylinkthisdrugwithhumanaging,butwestillneedtofindproof,saysKornfeldoptimistically.”
正确答案：E空前文字提出了文章的主题，也就是概括性地介绍了文章的内容：“一项研究表明治疗人类突发性疾病的药物能延缓虫子的衰老，由于人类的分子结构与虫子相似，所以有可能这种药物也能延缓人类的衰老”。只有选项E继续概括性地介绍了文章的内容：“这项研究同样也表明神经肌肉活动与衰老有关系”。
