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2022GMAT考试阅读题练习GMAT考试阅读题练习Althoughgeneticmutationsinbacteriaandvirusescanleadtoepidemics,someepidemicsarecausedbybacteriaandvirusesthathaveundergonenosignificantgeneticchange.Inanalyzingthelatter,scientistshavediscoveredtheimportanceofsocialandecologicalfactorstoepidemics.Poliomyelitis(poliomyelitis:n.小儿麻痹症,急性骨髓灰白质炎),forexample,emergedasanepidemicintheUnited第1页共6页Statesinthetwentiethcentury;bythen(bythen:到那时候),modernsanitationwasabletodelayexposuretopolio(POLIOMYELITIS)untiladolescenceoradulthood,atwhichtimepolioinfectionproducedparalysis.Previously,infectionhadoccurredduringinfancy,whenittypicallyprovidedlifelongimmunitywithoutparalysis.Thus,thehygienethathelpedpreventtyphoidepidemicsindirectlyfosteredaparalyticpolioepidemic.AnotherexampleisLymedisease,whichiscausedbybacteriathataretransmittedby第2页共6页deerticks.ItoccurredonlysporadicallyduringthelatenineteenthcenturybuthasrecentlybecomeprevalentinpartsoftheUnitedStates,largelyduetoanincreaseinthedeerpopulationthatoccurredsimultaneouslywiththegrowthofthesuburbsandincreasedoutdoorrecreationalactivitiesinthedeer’shabitat.Similarly,anoutbreakofdenguehemorrhagicfeverbecameanepidemicinAsiainthe1950’sbecauseofecologicalchangesthatcausedAedesaegypti,themosquitothattransmitsthedenguevirus,to第3页共6页proliferate.ThestageisnowsetintheUnitedStatesforadengueepidemicbecauseoftheinadvertentintroductionandwidedisseminationofanothermosquito,Aedesalbopictus.1.Thepassagesuggeststhatalackofmodernsanitationwouldmakewhichofthefollowingmostlikelytooccur?(A)AnoutbreakofLymedisease(B)Anoutbreakofdenguehemorrhagicfever(C)Anepidemicoftyphoid(D)Anepidemicofparalyticpolioamonginfants(C)第4页共6页(E)Anepidemicofparalyticpolioamongadolescentsandadults2.Accordingtothepassage,theoutbreakofdenguehemorrhagicfeverinthe1950’soccurredforwhichofthefollowingreasons?(A)ThemosquitoAedesaegyptiwasnewlyintroducedintoAsia.(B)ThemosquitoAedesaegyptibecamemorenumerous.(C)Themosqui第5页共6页本文来源：网络收集与整理，如有侵权，请联系作者删除，谢谢！第6页共6页