赠送题(二)阅读部分(1)

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1、阅读部分SectionⅡReadingComprehensionPartADirections:Readthefollowingfourtexts.AnswerthequestionsbeloweachtextbychoosingA,B,CorD.MarkyouranswersonANSWERSHEET1.(40points)一、从鸡蛋中培养流感疫菌Moderntechnologyhasputmenonthemoonanddecipheredthehumangenome.Butwhenitcomestobrewingupflutomakevaccines,

2、sciencestillturnstotheincredibleedibleegg.Eversincethe1940s,vaccinemakershavegrownlargebatchesofvirusinsidechickeneggs.Butgiventhatsome36,000Americansdieofflueachyear,it’sremarkablethatourfirstlineofdefenseisstillwhatSecretaryofHealthandHumanServicesTommyThompsoncalls“thecumbersom

3、eandarchaicegg-basedproduction.”Newcell-basedtechnologiesareinthepipeline,however,andmayfinallygetthesupporttheyneednowthattheUnitedStatesisfacedwithacriticalshortageoffluvaccine.Althoughexpertsdisagreeonwhethernewwaysofproducingvaccinecouldhavepreventedashortageliketheonehappenin

4、gtoday,thereisnodoubtthattheexistingsystemhasseriousflaws.Eachyear,vaccinemanufacturersplaceadvanceordersformillionsofspeciallygrownchickeneggs.Meanwhile,public-healthofficialsmonitorcirculatingstrainsofflu,andeachMarchtheyrecommendthreestrains—twoinfluenzaAstrainsandoneBstrain—fo

5、rmanufacturerstoincludeinvaccines.Inthelatespringandsummer,automatedmachinesinjectvirusintoeggsandlatersuckouttheinfluenza-richgoop.Virusfromtheeggs’innardsgetskilledandprocessedtoremoveeggproteinsandothercontaminantsbeforebeingpackagedintovialsforfallshipment.Whyhasthiseggmethodp

6、ersistedforsixdecades?Themainreasonisthatit’sreliable.Buteventhoughtheeggsarereliable,theyhaveseriousdrawbacks.Oneisthelongleadtimeneededtoordertheeggs.Thatmeansit’shardtomakemorevaccineinahurry,incaseofashortageorunexpectedoutbreak.Andeggsmaysimplybetoocumbersometokeepupwiththehu

7、ndredsofmillionsofdosesrequiredtohandlethedemandforfluvaccine.What’smore,someflustrainsdon’tgrowwellineggs.Lastyear,scientistswereunabletoincludetheFujianstraininthevaccineformulation.Itwasarelativelynewstrain,andmanufacturerssimplycouldn’tfindaquickwaytoadaptitsothatitgrewwelline

8、ggs.“Weknewthestrainwasoutthere,”