PassageOneQuestions46to50arebasedonthefollowingpassage.Aginghappenstoallofus,andisgenerallythoughtofasanaturalpartoflife.Itwouldseemsillytocallsuchathinga“disease.”Ontheotherhand,scientistsareincreasinglylearningthatagingandbiologicalagearetwodifferentthings,andthattheformerisakeyriskfactorforconditionssuchasheartdisease,cancerandmanymore.Inthatlight,agingitselfmightbeseenassomethingtreatable,thewayyouwouldtreathighbloodpressureoravitamindeficiency.BiophysicistAlexZhavoronkovbelievesthatagingshouldbeconsideredadisease.Hesaidthatdescribingagingasadiseasecreatesincentivestodeveloptreatments.“Ituntiesthehandsofthepharmaceutical(制药的)industrysothattheycanbegintreatingthediseaseandnotjustthesideeffects,”hesaid.‘‘Rightnow,peoplethinkofagingasnaturalandsomethingyoucan’tcontrol:’hesaid.“Inacademiccircles,peopletakeagingresearchasjustaninterestareawheretheycantrytodevelopinterventions.Themedicalcommunityalsotakesagingforgranted,andcandonothingaboutitexceptkeeppeoplewithinacertainhealthrange.”Butifagingwererecognizedasadisease,hesaid,“Itwouldattractfundingandchangethewaywedohealthcare.Whatmattersisunderstandingthatagingiscurable.”“Itwasalwaysknownthatthebodyaccumulatesdamage,”headded.“Theonlywaytocureagingistofindwaystorepairthatdamage.Ithinkofitaspreventivemedicineforage-relatedconditions.''LeonardHayflick,aprofessorattheUniversityofCalifornia,SanFrancisco,saidtheideathatagingcanbecuredimpliesthehumanlifespancanbeincreased,whichsomeresearcherssuggestispossible.Hayflickisnotamongthem.“There’remanypeoplewhorecoverfromcancer,stroke,orheartdisease.Buttheycontinuetoage,becauseagingisseparatefromtheirdisease,”Hayflicksaid.“Evenifthosecausesofdeathwereeliminated,lifeexpectancywouldstillnotgomuchbeyond92years.”注意:此部分试题请在答题卡2上作答。46.Whatdopeoplegenerallybelieveaboutaging?A)Itshouldcausenoalarmwhatsoever.B)Theyjustcannotdoanythingaboutit.C)Itshouldberegardedasakindofdisease.D)Theycandelayitwithadvancesinscience.
Althoughmanyofusmayfeelair-conditionersbringrelieffromhot,humidorpollutedoutsideair,theyposemanypotentialhealthhazards.Muchresearchhaslookedathowthemovementofairinsideaclosedenvironment---suchasanofficebuilding---canspreaddiseaseorexposepeopleinthebuildingtoharmfulchemicals.OneofthemorewidelypublicizeddangersisthatofLegionnaire’sdisease,whichwasfirstrecognizedinthe1970s.Thiswasfoundtohaveaffectedpeopleinbuildingswithair-conditioningsystemsinwhichwarmairpumpedoutofthesystem’coolingtowerswassomehowsuckedbackintotheairintake(通风口),inmostcasesduetopoordesign.Thewarmair,filledwithbacteria,wascombinedwithcooled,conditionedairandwasthencirculatedaroundvariouspartsofthebuilding.Studiesshowedthatevenpeopleoutsidesuchbuildingswereatriskiftheywalkedpastairexhaustpipes.Largeair-conditioningsystemsaddwatertotheairtheycirculatebymeansofhumidifiers(湿度调节器).Inoldersystems,thewaterusedforthisprocessiskeptinspecialreservoirs,thebottomsofwhichprovidebreedinggroundsforbacteriawhichcanfindtheirwayintotheventilation(通风)system.Therisktohumanhealthfromthissituationhasbeenhighlightedbythefactthattheimmunesystems(免疫系统)ofapproximatelyhalfofworkersinair-conditionedofficebuildingshavedevelopedtheabilitytofightofftheorganismsfoundatthebottomofsystemreservoirs.Butchemicalscalled“biocides”areaddedtoreservoirstomakethemgerm-free,andtheyaredangerousintheirownrightinsufficientquantities,astheyoftencontaincompoundsstronglylinkedtocancers.Finally,itshouldbepointedoutthattheartificialclimaticenvironmentcreatedbyair-conditionerscanalsoaffectus.Inanaturalenvironment,whetherindoororoutdoor,therearesmallvariationsintemperatureandhumidity.Indeed,thehumanbodyhaslongbeenaccustomedtothesenormalchanges.Inanair-conditionedlivingorworkingenvironment,however,bodytemperaturesremainwellunder37℃,ournormaltemperature.Thisleadstoaweakenedimmunesystemandthusgreaterexposuretodiseasessuchascoldsandflu.2.Intheoldair-conditionedsystems,bacteriafirstdevelop______.
2.The18thcenturyreallywasawaterbornecentury,the19thcenturyarailcentury,the20thcenturyahighway,car,truckcentury—andthe21stcenturywillincreasinglybeanaviationcentury,astheglobebecomesincreasinglyconnectedbyair,