好学教育：HYPERLINK"http://www.5haoxue.net"http://www.5haoxue.net2013职称英语考试理工a常用短语模拟题及答案1BeyondthePapScientistshaveknownforsometimethatvirtuallyallcasesofcervicalcanceraretriggeredbyafamilyofvirusescalledhumanpapillomavirus,orHPV.MostwomenwhobecomeineffectedwithHPVareabletoshakeoffthevirusandsuffernoapparentlong-termconsequencestotheirhealth.Butafewwomendevelopapersistentinfectionthatcan,forreasonsthatarenotentirelyclear,eventuallyleadtocancerouschangesinthecervix.NowresearchersattheDigeneCorpofBeltsville,Maryland,havedevelopedatestthatdetectsanactiveHPVinfectionbylookingforitsgeneticbyproductsinthevagina.TheHPVtestwasbetterthanthestandardPaptestatfindingcervicalcanceratanystage,accordingtotwostudiespublishedthismonthintheJournaloftheAmericanMedicalAssociation.Sofar,sogood.Unfortunately,thetest'sfalse-positiverate—howoftenitindicatedthattherewasaproblemwhennoneexistedwasalmosttwiceashighasthatforthePapsmear.Inthesecases,abiopsyofthewoman’scervixshowednosignofdisease.Andthat’sthecruxoftheproblem.Howmanywomenshouldundergowhatis,whenitcomesrightdowntoit,unnecessarytreatmenttofindafewmorecasesofcervicalcancer?Shouldn’thealthofficialsfocusinsteadonmakingsurethatmorewomenundergoregularPap-smearexaminations?Afterall,Papsmears,thoughfarfromperfect,havehelpeddramaticallylowerthedeathtollfromcervicalcancertakingitfromtheNo.1causeofdeathduetocancerinAmericanwomentothe10th.ComplicatingmattersisthefactthatHPVisaverycommoninfection.InsomepartsoftheU.S.asmanyashalfofallwomenunderage35haveanactivecase.Yet99outof100womenwhoareHPV-positivewillnevergetcervicalcancer,estimatesDr.JoannaCain,vicepresidentoftheAmericanCollegeofObstetriciansandGynecologists.“Ifthose99womenlivetheirlivesasifthey’regoingtodevelopcancer”,shesays,“we’renotnecessarilydoingthemanygood.”Atpresent,theHPVtestisapprovedintheU.S.onlytohelpresolveambiguousresultsfromaPap-Smeartest.ManygynecologistsbelievethatHPVwilleventuallyreplacethepap.Butthey’renotwillingtoabandonitwithoutalotmoredetailedinformationandn