大学英语四级考试备考练习Word文档下载推荐.docx
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3.我认为,电动车……
PartIIReadingComprehension(SkimmingandScanning)(15minutes)
Inthispart,youwillhave15minutestogooverthepassagequickly.Forquestions1-7,choosethebestanswerfromthefourchoicesmarkedA),B),C)andD).Forquestions8-10,completethesentenceswiththeinformationgiveninthepassage.
FluPrevention:
5CriticalLessonsfromHistoryandWhatTheyMeanToday
It’simpossibletopredictwhatafluvirusisgoingtodo.Buthistoryoffersacriticalguideanyway,showingpublichealthofficialswhichmovesarelikelytopayoffinthebattleagainstthedisease.
1.Whatworks:
Shuttingthingsdown
Intheso-calledSpanishfluepidemicof1918-1919,threewavesofthediseaseswepttheworld,killingapproximately50millionpeople,including500,000Americans.ButMinneapolisandMilwaukeesufferedfewerthan3deathsper1,000people—lessthanhalftherateincitieslikeBaltimore,BostonandSanFrancisco.
Onereason:
TheMidwesterncitiesquarantinedthesick,closedschoolsandchurches,andbannedpublicgatherings.Anothercity,Gunnison,Colorado,escapedtheplaguebyphysicallyblockingthemainroadsintotown.Ontheotherhand,Philadelphiaofficialsrefusedtobanmeetingsorparadesongroundsofpatriotism,andcitynewspapersdownplayedtheflu’sseverity.Theresult:
Philadelphiahadoneofthehighestdeathratesinthecountry.Thesemeasureshavecost,ofcourse:
Closingschoolscouldforcesomanyparentstomissworkthatitcouldhamstringtheeconomy.Ifthevirusdoesn’tintensify,U.S.officialssay,theiradviceistokeepschoolsopenasmuchaspossible.
Take-homelesson:
Askyourkids’principalwhatwouldtriggeraschoolclosing,andbeprepared.Strategizewithfriendsaboutsharingchildcareiftheneedarises,ortalktoyourbossaboutworkingfromhome.
2.Whatworks:
Vaccinating(给……接种疫苗)kidsearly
WhogetsflushotsintheUnitedStates?
Oldpeople,ofcourse—they’vebeenthefocusoffluvaccinecampaignssincethe1960s.Butanimportantwaytoincreasetheirprotection,ironically,istovaccinatetheirchildrenandgrandchildren.
Thereason:
Anolderperson’simmunesystemdoesn’trespondefficientlytothefluvaccine,soit’sonlypartiallyprotective.Thesamevaccinecreatesamuchstrongerimmunityintheyoung.What’smore,kidsaremorelikelythanotherstobecomesilentcarriers,transmittingthevirusforuptotendaysaftersymptomsdisappear.
It’sworthgettingyourfamilyvaccinatedevenifthefluseemsmild,ifonlybecauseinsomepandemics,thesecondwavehasbeendeadlierthanthefirstone.TheCentersforDiseaseControlandPrevention(orCDC)advocatesthatchildrenandyoungadultsbeamongthefirstgroupofpeopletoreceivethevaccine.Someoftheothersontheprioritylistincludepeoplewithchronicillnesses,likediabetesandheartorlungdisease,andpregnantwomen,allofwhomareathighriskofcomplications(并发症)ofthepandemicflu.
3.Whatworks:
Avaccinethatcan’tbefooled
Everyyear,peopleunluckyenoughtobeinfectedwiththefludevelopantibodiesthatwillkeepthemsafeifthey’reexposedtothesamevirusinthefuture.Butgradually,thevirusmutates(变异)—sometimesenoughtofoolthoseantibodiesandinfectthepeopleagain.Asaresult,virologistsandpublichealthofficialsarealwaysplayingcatch-up.InFebruary,theypredictwhichstrainsofviruswillcirculateinthefall,anddrugcompaniespreparevaccinestoproduceimmunitytothosespecificstrains.Inevitably,thepredictionssometimesprovewrong.“Itwouldbeahugeadvantagetohaveauniversalvaccine,”saysE.JohnWherry,PhD,oftheWistarInstituteinPhiladelphia—avaccinethatwouldprotectyearinandyearout,byaimingatpiecesofthevirusthatdon’tchange.Likehundredsofscientistsaroundtheworld,Dr.Wherryistryingtodevelopsuchavaccine.It’sstillalongwayoff,butapartialsolutionmayalreadybeavailable.Whenavaccineismixedwithanadjuvant(achemicalmixturethatstimulatestheimmunesystem),ashasbeendoneinstudiesofbirdfluvaccine,itseemstoprotectagainstavarietyoffluviruses.Soevenifthecurrentvirusmutates,anadjuvantvaccinemightstillprovideashield.
Adjuvantvaccinesaren’tlicensedintheUnitedStates,andtheFoodandDrugAdministrationprobablywon’tletususethemunlessthevirusbecomesmoreserious.(However,thereseemstobesomenaturalcross-protectiongoingonwiththisvirus:
Thoughnewtohumanimmunesystems,itdoesn’tseemtoinfectpeopleover60veryoften.Theearlierfluvirustaughttheirimmunesystemsawaytodefendagainstthecurrentone.)Thebestwaytoboostyourprotection:
Washyourhandsoften—thefluviruscansurviveupto48hoursonsurfaces.Getplentyofsleepandtakeregularexercise;
yourimmunesystemdependsonthem.
4.Whatworks:
Ahealthyrespectforsideeffects
OnebalmynightinNovember1976,39-year-oldJuneE.Robertsfeltcoldnessinherfingersasshetriedtopaysomebills.Itwastwoweeksaftershe’dgottenavaccineagainstthecountry’sfirstoutbreakofswineflu.Thenextmorning,theMcLean,Virginia,tennisinstructorcouldn’tgetoutofbed.Formorethanamonth,Robertscouldn’teat,moveherlimbs,orevenclosehereyes.Sherecovered,slowly,butwasneverabletoplaytenniswellagain.RobertshadGuillain-Barré
syndrome,adisorderinwhichantibodiesattackthepatient’sownnervoussystem.Itwastriggeredbythefluvaccinesheandmorethan40millionotherAmericanshadgotten.NoonewasentirelysurewhythevaccinecausedGuillain-Barré
syndrome,butitaffectedmorethan500peopleandkilledabout25.(Thefearedswinefluepidemicnevermaterializedthatyear.)Theepisodehashighlightedapointfamiliartopublichealthworkers:
Preventionnevercomeswithoutrisk.
TheCDCisaddingstaffandcomputertrackingsystemstolookforpossibleproblemswiththevaccine,soifanyunexpecteddangersshowup,they’llbeflaggedquickly.Butexpertsemphasizethatit’srareforanyfluvaccinetohaveserioussideeffects,andtheydon’texpecttoseeanywiththisvaccine.Specifically,theydon’tanticipatecasesofGuillain-Barré
syndrome,becauseofmajordifferencesbetweenthisyear’sswinefluvirusandtheonethatpromptedthe1976vaccine.
5.Whatworks:
Localcontrol
Althoughyou’rehearingalotfromtheCDCandtherestofthefederalgovernment—nottomentiontheWorldHealthOrganization—abouthowtorespondtotheflu,therealdecisionswillbemadebystatesandlocalities.“Everythingislocal,”saysformerCDCdirectorDavidSencer,MD.“Thefederalgovernmentcangiveguidance,butimplementationhastobelefttothelocalcommunities.Whichkeyemergencyworkersshouldbeimmunized?
IfyouaskmydaughterinMinneapolis,she’llsayit’sthesnowplowdrivers.Ifyoucan’tmovearoundthecity,youcan’ttakecareofsickkids.”Thedownsideisthatwithstates,cities,andevenschooldistrictsformulatingtheirownpolicies,we’relikelytohearconflictingadvice.
Takeadeepbreathandgetpreparedforsomeconfusion.Tohelpsortthroughthings,youcanfindhelpfulinformationatcentralclearinghouses.
1.Accordingtothepassage,MinneapolisandMilwaukee________.
A)didverywellincombatingtheSpanishflu
B)didn’tdoagoodjobfightingtheSpanishflu
C)didnothingtostrugglewiththeSpanishflu
D)refusedtobanmeetingsorparades
2.Whatshouldparentsdoiftheirchildren’sschoolsareclosed?
A)Asktheirkids’principalwhentheschoolswillreopen.
B)Talktotheirbossaboutraisingtheirsalarytotakecareofkids.
C)Preparetoalternatewiththeirfriendsintakingcareofkids.
D)Quittheirjobsandstayathomewiththeirchildren.
3.ManypeopleshouldreceivethevaccinefirstEXCEPT________.
A)peoplewithchronicillnesses
B)childrenandyoungadults
C)pregnantwomen
D)oldpeople
4.Theunderlinedphrase“playingcatch-up”mostprobablymeans“________”.
A)playingcomputergames
B)playingcards
C)predictingepidemicdiseases
D)catchingepidemicpatients
5.Itwouldbegreattohaveauniversalvaccinebecause___________.
A)itwouldprotectpeopleyearinandyearout
B)theexpertswouldn’tneedtopredictwhichviruswillcirculate
C)theviruswouldnotmutateandinfectpeopleagain
D)peoplewouldn’tneedtoreceivethevaccineanymore
6.Youmayimproveyourimmunesystemthroughthefollowingways,EXCEPT_______.
A)washingyourhandsoften
B)gettingplentyofsleep
C)eatingabalanceddiet
D)gettingregularexercise
7.ThestoryofJuneE.Robertsisgivento__________.
A)provethisyear’sswinefluvirusismild
B)criticizetheU.S.governmentofficials
C)stressthatpreventionnevercomeswithoutrisk
D)implythatpeopleshouldn’treceivethevaccine
8.____________________schoolsandbanningpublicgatheringsareeffectivewaystofightagainstafluvirus.
9.Expertsclaimthatnotallfluvaccineshaveserious______________.
10.Althoughthefederalgovernmentcangiveguidance,implementationhastobeleftto_________________.
PartIIIReadingComprehension(ReadinginDepth)(25minutes)
■SectionA
Inthissection,thereisapassagewithtenblanks.Youarerequiredtoselectonewordforeachblankfromalistofchoicesgiven