大学英语试题3答案!quiz3
Polio(小儿麻痹症)wasoneofthemostfeareddiseasesofthefirsthalfofthe20thcentury.Itappeared21.bychancebyturnsbymistake,mostlyinchildren,causingparentstoworryduringtheepidemicsofthe1940sand1950s.PresidentFranklinDelanoRooseveltcaughtthediseasein1921.Hewas22.remainedleftgotwithouttheuseofhislegs.
Differenttowhatiscommonlybelieved,poliodidnottypically23.resultinemergeinhappeninseriousdamagetoone'slegs.24.RatherthanInplaceofRather,themajorityofindividualswhocaughtitonly25.implementedexperiencedexperimentedsmallproblems,suchasfeverandheadache.Thesedifficultiesonly26.wentpassedlastedafewdays,andmanyhadsuchsmallcases27.thatwhichsotheydidnotevenrealizetheywereill.28.ThereforeHoweverInsuch,theyoftencontinued29.duringwhilewiththeirdailylives,attendingschoolorwork,unknowinglygivingmanyothersthevirus.Thisexplains30.whenwhyhowmanypeoplewhohadseriouscasesofpoliobelievedthattheyweretheonlyoneintheirfamily,neighborhood,orcommunitytohave31.haddonesufferedthedisease.Intruth,therecouldhavebeenmanyindividuals32.fortowithwhomtheycameintocontactthathadtheillness,33.sincesobutdidnotshowsymptoms.
In1948,JonasSalk34.madestartedworkedresearchonavaccineforthedisease.35.AfterallThanThenin1955,theSalkvaccinewasshowntobe36.operativeefficiencyeffectiveinpreventingthediseaseaftertrials37.involvingaffectingprotectingnearlytwomillionchildren.Anationwideprogramtovaccinate(接种疫苗)wasquicklystartedand38.sinceafterbeforeseveralyearsandimprovementsonthevaccinebyAlbertSabin,theUnitedStateswasalmostentirely39.ridofdoneawayputanendtothedisease.Today,polioisallbutforgotten,asithas40.completelyrelativelyinevitablydisappeared
