Thediscoverythatthedrugsextendthelifespanofroundwormscouldhaveimportantimplicationsfoxhumanagingaswell.Therearestr ongsimilaritiesonthemolecularlevelbetweentheproteinsandgenesthat
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：B空前文字一直提到实验的进程和结果，选项B进一步提到了这次实验的结果。同现原则，这一空的正确选项应该是B。
