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1、2016年职称英语考试综合类阅读理解考试试题及答案 EattoLive Ameagerdietmaygiveyouhealthandlonglife,butit'snotmuchfun—anditmightnotevenbenecessary.Wemaybeabletohangontomostofthatyouthfulvigorevenifwedon'tstarttodietuntiloldage. StephenSpindlerandhiscolleaguesfromtheUniversityofCaliforniaatRiversidehavefoundthatsomeof
2、anelderlymouse'slivergenescanbemadetobehaveastheydidwhenthemousewasyoungsimplybylimitingitsfoodforfourweeks.Thegeneticrejuvenationwon'treverseotherdamagecausedbytimeforthemouse,butcouldhelpitslivermetabolizedrugsorgetridoftoxins. Spindler'steamfedthreemiceanormaldietfortheirwholelives,andfedano
3、therthreeonhalf-rations.Threemoremicewereswitchedfromthenormaldiettohalf-feedforamonthwhentheywere34monthsold—equivalenttoabout70humanyears. Theresearcherscheckedtheactivityof11,000genesfromthemouselivers,andfoundthat46changedwithageinthenormallyfedmice.Thechangeswereassociatedwiththingslikeinf
4、lammationandfreeradicalproduction—probablybadnewsformousehealth.Inthemicethathaddietedalltheirlives,27ofthose46genescontinuedtobehavelikeyounggenes.Butthemostsurprisingfindingwasthatthemicethatonlystarteddietinginoldagealsobenefitedfrom70percentofthesegenechanges. “Thisisthefirstindicationthatt
5、heeeffectskickinprettyquickly,”saysHuberWarnerfromtheNationalInstituteonAgingnearWashington,D.C. Nooneyetknowsifcalorieworksinpeopleasitdoesinmice,busSpindlerishopeful.“There'sattractingandtemptingevidenceouttherethatitwillwork,”hesays. Ifitdoesworkinpeople,theremightbegoodreasonsforrejuvenati
6、ngtheliver.Aswegetolder,outbodiesarelesefficientatmetabolizingdrugs,forexample.Abriefperiodoftimeofdieting,saysSpindler,couldbeenoughtomakesureadrugiseffective. ButSpindlerisn'tsurethetrade-offisworthit.“Themicegetlessdisease,theylivelongerbutthey'rehungry,”hesays.“Evenseeingwhatadietdoes,it'ss
7、tillhardtogotoarestaurantandsay:'Icanonlyeathalfofthat'.” Spindlerhopeswesoonwon'tneedtodietatall.Hiscompany,LifeSpanGeneticsinCalifornia,islookingfordrugsthathavetheeffectsofcalorierestriction. 1.Accordingtothepassage,whi