2018 年6 月大学英语四级考试真题及答案（三）

2018年6月大学英语四级考试真题（三）PartI Writing (30minutes)Directions:Forthispart,youallowed30minutestowriteashortessayontheimportanceofspeakingabilityandhowtodevelopit.shouldwriteatleast120wordsbutnothan180words.PartⅡ ListeningComprehension (25minutes)特别说明：由于四级考试全国共考了两套听力，本套真题听力与前两套内容相同，只是选项顺序不同，故不再重复给出。PartⅢ ReadingComprehension (40minutes)SectionADirections:Inthissection,isapassagewithtenblanks.toselectoneforeachblankalistofchoicesgiveninabankfollowingthepassage.Readthepassagethroughcarefullybeforemakingyourchoices.EachchoiceinthebankisidentifiedbyaPleasemarkthecorrespondingletterforeachitemonAnswerSheet2withasinglelinethroughthecentre.maynotuseanyofthewordsinthebankmorethanonce.Neon(虹)istoHongKongasredphoneboothsaretoLondonandfogistoSanFrancisco.Whennightfalls,redandblueandothercolors26 ahazy(蒙的)glowoveracitylitupbytensofthousandsofneonsigns.Butmanyofthemaregoingdark,27 bymorepractical,butlessromantic,LEDs(发光二极管).Changingbuildingcodes,evolvingtastes,andthehighcostofmaintainingthosewonderfuloldsignshavebusinessesembracingLEDs,whichareenergy28 ,butstillcarrygreatcost.me,neonrepresentsmemoriesofthepast,”saysphotographerSharonBlance,whoseseriesHongKongNeoncelebratesthefamoussigns.“LookingatthesignsnowIgetafeelingofamazement,mixedwithsadness.”Buildinganeonsignisanartpracticedby29 trainedonthejobtomoldglasstubesinto30 shapesandletters.Theyfillthesetubeswithgasesthatglowwhen31 .Neonmakesorange,whileothergasesmakeyelloworblue.Ittakesmanyhourstocraftasinglesign.BlancespentaweekinHongKongand32 morethan60signs;22ofthemappearintheseriesthatcapturethesignslightinguplonelystreets–an33 thatmakesiteasytoadmiretheircolorsandcraftsmanship.“Ilovethebeautiful,handcrafted,old-fashioned34 ofneon,”saysBlance.Thesignsdonothingmorethan35 arestaurant,theater,orotherbusiness,butdosointhemoststrikingwaypossible.H)identifyH)identifyO)volunteersG)electrifiedN)symbolizesF)efficientM)stimulateE)decorativeL)replacedD)challengingK)qualityC)castJ)professionalsB)approachI)photographedA)alternativeSectionBDirections:Inthissection,youaregoingtoreadapassagewithtenstatementsattachedtoit.Eachstatementcontainsinformationgiveninoneoftheparagraphs.Identifytheparagraphfromwhichtheinformationisderived.Youmaychooseaparagraphmorethanonce.Eachparagraphismarkedwithaletter.AnswerthequestionsbymarkingthecorrespondingletteronAnswerSheet2.NewJerseySchoolDistrictEasesPressureonStudents–BaringanEthnicDivideThisfall,DavidAderhold,thechiefofahigh-achievingschooldistrictnearPrinceton,Newsentparentsanalarming16Theschooldistrict,hesaid,wasfacingacrisis.Itsstudentswereoverburdenedandstressedout,havingtocopewithtoomuchworkandtoomanydemands.Inthepreviousschoolyear,120middleandhighschoolstudentswererecommendedformentalhealthassessmentsand40werehospitalized.Andonasurveyadministeredbythedistrict,studentswrotethingslike,“Ihategoingtoschool,”and“Comingoutof12yearsinthisdistrict,Ihavelearnedonething:thatagrade,apercentageorevenapointistobevaluedoveranythingelse.”hisletter,AderholdinsertedWindsor-PlainsboroRegionalSchoolDistrictintoanationaldiscussionabouttheintensefocusonachievementateliteschools,andwhetherithasgonetooAtfollow-upmeetings,heurgedparentstojoinhiminadvocatinga“wholechild”approachtoschoolingthatrespects“social-emotionaldevelopment”and“deepandmeaningfullearning”overacademicsalone.Thealternative,hesuggested,wastofacetheprospectofbecominganotherPaloAlto,California,whereoutsizestressonteenagestudentsisbelievedtohavecontributedtoanumberofsuicidesinthelastsixyears.Butinsteadofbringingfamiliestogether,Aderhold’sletterrevealedadivideinthedistrict,whichhas9,700students,andonethatbrokedownroughlyalongraciallines.OnonesidearewhiteparentslikeCatherineaformerpresidentoftheParent-Teacher-StudentAssociationatherdaughter’smiddleschool,whohascometoseethedistrict’sincreasinglypressuredatmosphereasopposedtolearning.“Mysonwasinfourthgradeandtoldme,‘I’mnotgoingtoamounttoanythingbecauseIhavenothingtoputonmyrésumé,’”shesaid.OntheothersideareparentslikeMikeJia,oneofthethousandsofAsian-Americanprofessionalswhohavemovedtothedistrictinthepastdecade,whosaidAderhold’sreformswouldamounttoa“dumbingdown”ofhischildren’seducation.“Whatishappeningherereflectsanationalanti-intellectualtrendthatwillnotprepareourchildrenforthefuture,”Jiasaid.About10minutesfromPrincetonandanhourandahalffromNewWindsorandPlainsborohavebecomepopularbedroomcommunitiesfortechnologyentrepreneurs,researchersandengineers,drawninlargepartbythepublicschools.Fromthelastthreegraduatingclasses,16seniorswereadmittedtoItproducesScienceOlympiadwinners,classicallytrainedmusiciansandstudentswithperfectscores.ThedistricthasbecomeincreasinglypopularwithimmigrantfamiliesfromChina,IndiaandKorea.Thisyear,65percentofitsstudentsareAsian-American,comparedwith44percentin2007.ManyofthemarethefirstintheirfamiliesbornintheUnitedStates.Theyhavehadagrowinginfluenceonthedistrict.Asian-Americanparentsareenthusiasticsupportersofthecompetitiveinstrumentalmusicprogram.Theyhavebeenhugesupportersofthedistrict’sadvancedmathematicsprogram,whichoncebeganinthefourthgradebutwillnowstartinthesixth.Thechangetotheprogram,inwhich90percentoftheparticipatingstudentsareAsian-American,isoneofAderhold’sreforms.Asian-Americanstudentshavebeeneagerparticipantsinastateprogramthatpermitsthemtotakesummerclassesoffcampusforhighschoolcredit,allowingthemtomaximizethenumberofhonorsandAdvancedPlacementclassestheycantake,anotherpracticethatAderholdislimitingthisschoolmanyAsian-Americanchildrenattendingsupplementaryinstructionalprograms,thereisaperceptionamongsomewhitefamiliesthattheelementaryschoolcurriculumisbeingspeduptoaccommodatethem.BothAsian-Americanandwhitefamiliessaythetensionbetweenthetwogroupshasgrownsteadilyoverthepastfewyears,asthenumberofAsianfamilieshasrisen.ButthedivisionhasbecomemoreobviousinrecentmonthsasAderholdhasmadechanges,includingno-homeworknights,anendtohighschoolmidtermsandfinals,andaninitiativethatmadeiteasiertoparticipateinthemusicprogram.JenniferLee,professorofsociologyattheUniversityofCalifornia,Irvine,andanauthorofTheAsianAmericanAchievementParadox,saysmisunderstandingsbetweenfirst-generationAsian-Americanparentsandthosewhohavebeeninthiscountrylongerarecommon.Whatwhitemiddle-classparentsdonotalwaysunderstand,shesaid,ishowmuchpressurerecentimmigrantsfeeltoboosttheirchildrenintothemiddleclass.“Theydon’thavethesamechancestogettheirchildreninternships(实习职位)orjobsatlawfirms,”Leesaid.“Sowhattheybelieveisthattheirchildrenmustexcelandbeattheirwhitepeersinacademicsettingssotheyhavethesamechancestoexcellater.”TheissueofthestressesfeltbystudentsineliteschooldistrictshasgainedattentioninrecentyearsasschoolsinplaceslikeNewton,Massachusetts,andPaloAltohavereportedanumberofsuicides.Windsor-Plainsborohasnothadateenagesuicideinrecentyears,butAderhold,whohasworkedinthedistrictforsevenyearsandbeenchiefforthelastthreeyears,saidhehadseentroublingsigns.Inarecentartassignment,amiddleschoolstudentdepicted(描绘)anoverburdenedchildwhowasbeingscoldedforearninganA,ratherthananA+,onamathexam.Intheimage,themotherscoldsthestudentwiththewords,“Shameonyou!”Further,hesaid,theNewJerseyEducationDepartmenthasflaggedatleasttwopiecesofwritingonstateEnglishlanguageassessmentsinwhichstudentsexpressedsuicidalthoughts.Thesurveycommissionedbythedistrictfoundthat68percentofhighschoolhonorandAdvancedPlacementstudentsreportedfeelingstressedaboutschool“alwaysormostofthetime.”needtobringbacksomebalance,”Aderholdsaid.don’twanttowaituntiltoolatetodosomething.”Notallpublicopinionhasfallenalongraciallines.KarenSue,theChinese-Americanmotherofafifth-graderandaneighth-grader,believesthecompetitionwithinthedistricthasgottenoutofcontrol.Sue,whowasbornintheUnitedStatestoimmigrantparents,wantsherpeerstodialitback.becomeanarmsrace,aneducationalarmsrace,”shesaid.allwantourkidstoachieveandbesuccessful.Thequestionis,atwhatcost?”Aderholdislimitingtheextraclassesthatstudentsareallowedtotakecampus.WhiteandAsian-AmericanparentsrespondeddifferentlytoAderhold’sappeal.Suicidalthoughtshaveappearedinsomestudents'writings.Aderhold’sreformoftheadvancedmathematicsprogramwillaffectAsian-Americanstudentsmost.Aderholdappealedforparents’supportinpromotinganall-rounddevelopmentofchildren,insteadoffocusingonlyontheiracademicperformance.OneChinese-AmericanparentthinksthecompetitioninthedistricthasgonetooImmigrantparentsbelievethatacademicexcellencewillallowtheirchildrenequalchancestosucceedinthefuture.ManybusinessmenandprofessionalshavemovedtoWindsorandPlainsborobecauseofthepublicschoolsthere. AnumberofstudentsinAderhold’sschooldistrictwerefoundtohavestress-inducedmentalhealthproblems.ThetensionbetweenAsian-Americanandwhitefamilieshasincreasedinrecentyears.SectionCDirections:Thereare2passagesinthissection.Eachpassageisfollowedbysomequestionsorunfinishedstatements.ForeachofthemtherearefourchoicesmarkedA),B),C)andD).YoushoulddecideonthebestchoiceandmarkthecorrespondingletteronAnswerSheet2withasinglelinethroughthecentre.PassageOneQuestions46to50arebasedonthefollowingpassage.Forthousandsofyears,peoplehaveknownthatthebestwaytounderstandaconceptistoexplainittosomeoneelse.“Whileweteach,welearn,”saidRomanphilosopherSeneca.Nowscientistsarebringingthisancientwisdomup-to-date.They’redocumentingwhyteachingissuchafruitfulwaytolearn,anddesigninginnovativewaysforyoungpeopletoengageininstruction.Researchershavefoundthatstudentswhosignuptotutorothersworkhardertounderstandthematerial,recallitmoreaccuratelyandapplyitmoreeffectively.Studentteachersscorehigheronteststhanpupilswho’relearningonlyfortheirownsake.Buthowcanchildren,stilllearningthemselves,teachothers?Oneanswer:Theycantutoryoungerkids.Somestudieshavefoundthatfirst-bornchildrenaremoreintelligentthantheirlater-bornsiblings(兄弟姐妹).ThissuggeststheirhigherIQsresultfromthetimetheyspendteachingtheirsiblings.Noweducatorsareexperimentingwithwaystoapplythismodeltoacademicsubjects.Theyengagecollegeundergraduatestoteachcomputersciencetohighschoolstudents,whointurninstructmiddleschoolstudentsonthetopic.Butthemostcutting-edgetoolunderdevelopmentisthe“teachableagent”–acomputerizedcharacterwholearns,tries,makesmistakesandasksquestionsjustlikeareal-worldpupil.Computerscientistshavecreatedananimated(动画的)figurecalledBetty’sBrain,whohasbeen“taught”aboutenvironmentalsciencebyhundredsofmiddleschoolstudents.StudentteachersaremotivatedtohelpBettymastercertainmaterials.Whilepreparingtoteach,theyorganizetheirknowledgeandimprovetheirownunderstanding.Andastheyexplaintheinformationtoit,theyidentifyproblemsintheirownthinking.Feedbackfromtheteachableagentsfurtherenhancesthetutors’learning.Theagents’questionscompelstudenttutorstothinkandexplainthematerialsindifferentways,andwatchingtheagentsolveproblemsallowsthemtoseetheirknowledgeputintoaction.Aboveall,theemotionsoneexperiencesinteachingthatfacilitatelearning.Studenttutorsfeelupsetwhentheirteachableagentsfail,buthappywhenthesevirtualpupilssucceedastheyderiveprideandsatisfactionfromsomeoneelse'saccomplishment.Whatareresearchersrediscoveringthroughtheirstudies?thinkingisstillapplicableC)Humanintelligencetendstogrowwithage.Betterlearnerswillbecomebetterteachers. D)Philosophicalthinkingimprovesinstruction.WhatdowelearnaboutBrain?Itisacharacterinapopularanimation. C)Itisacutting-edgeappindigitalgames.Itisateachingtoolunderdevelopment. D)Itisatutorforcomputersciencestudents.Howdoesteachingothersbenefitstudenttutors?Itmakesthemawareofwhattheyarestrongat.Itmotivatesthemtotrynovelwaysofteaching.IthelpsthemlearntheiracademicsubjectsItenablesthemtobetterunderstandtheirteachers.Whatdostudentsdototeachtheirteachableagents?Theymotivatethemtothinkindependently.Theyaskthemtodesigntheirownquestions.Theyencouragethemtogivepromptfeedback.Theyusevariouswaystoexplainthematerials.Whatisthekeyfactorthateasesstudenttutors’learning?Theirsenseofresponsibility. C)Thelearningstrategyacquired.Theiremotionalinvolvement. D)Theteachingexperiencegained.PassageTwoQuestions51to55arebasedonthefollowingpassage.Anewbatchofyoungwomen–membersoftheso-calledMillennial(千禧的)generation–hasbeenenteringtheworkforceforthepastdecade.Atthestartinglineoftheircareers,theyarebettereducatedthantheirmothersandgrandmothershadbeen–orthantheiryoungmalecounterpartsareButwhentheylookahead,theyseeroadblockstotheirsuccess.Theybelievethatwomenarepaidlessthanmenfordoingthesamejob.Theythinkeasierformentogettopexecutivejobsthanitisforthem.Andtheyassumethatifandwhentheyhavechildren,itwillbeevenharderforthemtoadvanceintheircareers.Whilethepublicseesgreaterworkplaceequalitybetweenmenandwomennowthanitdid20–30yearsago,mostbelievemorechangeisneeded.AmongMillennialwomen,75%saythiscountryneedstocontinuemakingchangestoachievegenderequalityintheworkplace,comparedwith57%ofMillennialmen.Evenso,relativelyfewyoungwomen(15%)saytheyhavebeendiscriminatedagainstatworkbecauseoftheirgender.AsMillennialwomencomeofagetheysharemanyofthesameviewsandvaluesaboutworkastheirmalecounterparts.Theywantjobsthatprovidesecurityandflexibility,andtheyplacerelativelylittleimportanceonhighpay.Atthesametime,however,youngworkingwomenarelesslikelythanmentoaimattopmanagementjobs:34%saythey’renotinterestedinbecomingabossortopmanager;only24%ofyoungmensaythesame.Thegendergaponthisquestionisevenwideramongworkingadultsintheir30sand40s,whenmanywomenfacethetrade-offsthatgowithworkandmotherhood.ThesefindingsarebasedonanewPewResearchCentersurveyof2,002adults,including810Millennials(ages18–32),conductedOct.7–27,2013.Thesurveyfindsthat,inspiteofthedramaticgainswomenhavemadeineducationalattainmentandlaborforceparticipationinrecentdecades,youngwomenviewthisasaman’sworld–justasmiddle-agedandolderwomendo.WhatdowelearnfromthefirstparagraphaboutMillennialwomenstartingtheircareers?Theycangetaheadonlybystrivingharder.TheyexpecttosucceedjustlikeMillennialmen.Theyaregenerallyquiteoptimisticabouttheirfuture.Theyarebettereducatedthantheirmalecounterparts.HowdomostMillennialwomenfeelabouttheirtreatmentintheworkplace?Theyarethetargetofdiscrimination. C)Theythinkitneedsfurtherimproving.Theyfinditsatisfactoryonthewhole. D)Theyfindtheircomplaintsignored.WhatdoMillennialwomenvaluemostwhencomingofage?Asenseofaccomplishment. C)Rewardsandpromotions.JobstabilityandD)Joyderivedfromwork.Whatarewomenintheir30sand40sconcernedabout?Thewelfareoftheirchildren. C)Thefulfillmentoftheirdreamsinlife.Thenarrowingofthegendergap. D)ThebalancebetweenworkandWhatconclusioncanbedrawnaboutMillennialwomenfromthe2013survey?Theystillviewthisworldasonedominatedbymales.Theyaccountforhalftheworkforceinthejobmarket.Theyseetheworlddifferentlyfromoldergenerations.Theydobetterinworkthantheirmalecounterparts.PartⅣ Translation (30minutes)Directions:Forthispart,youareallowed30minutestotranslateapassagefromChineseintoEnglish.YoushouldwriteyouransweronAnswerSheet2.近年来，中国有越来越多的城市开始建设地铁。发展地铁有助于减少城市的交通拥堵和空气污染。地铁具有安全、快捷和舒适的优点。越来越多的人选择地铁作为每天上班或上学的主要交通工具。如今，在中国乘坐地铁正变得越来越方便。在有些城市里，乘客只需用卡或手机就可以乘坐地铁。许多当地老年市民还可以免费乘坐地铁。2018年6月大学英语四级考试真题（三）PartI Writing (30minutes)【高分范文】TheImportanceofSpeakingAbilityandHowtoDevelopItThereisnodenyingthatspeakingabilityisoneofthemostcriticalcommunicationskillsonmanyoccasions,suchasbusinesses,familiesandsoforth.Thereasonwhyspeakingabilityissocrucialisthatindailylife,mostinteractionsdependonhowmenandwomenspeak.goodspeakingonecanfindthathisorhernewperspectivescanbevividlyexpressed,sotheirsuggestionswillbeeasilyaccepted.Meanwhile,heorshewillbeconsideredasaneloquenttalent.Nothingismoreindispensableforlifeandcareerthanimprovingspeakingbeginwith,wearesupposedtolistenmore,suchasfamousspeeches,newsreportsandsoon,forlisteningiscloselyrelatedtospeaking.Besides,constantpracticeinreadingandrecitingisessentialandbeneficialforourcriticalthinking.Lastbutnottheleast,weoughttomakeitaruletomakefriendsprovidedwehaveanopportunitytoseeklanguagepartners.Formypart,associalbeings,onnoaccountcanweignorethevalueofspeakingOnlywhenweimprovespeakingabilitycanweachieveagreatersuccess.PartⅡ ListeningComprehension (25minutes)特别说明：由于四级考试全国共考了两套听力，本套真题听力与前两套内容相同，只是选项顺序不同，故不再重复给出。PartⅢ ReadingComprehension (40minutes)SectionA【参考答案】CLFJE GIBKHSectionB【参考答案】FCIEB KHDAGSectionC【参考答案】ABCDB DCBDAPartⅣ Translation (30minutes)【高分译文】Inrecentyears,moreandmoreChinesecitieshavestartedtobuildsubwaysasawaytoreducetrafficjams/gridlockandairpollution.Agrowingnumberofpeoplenowchoosesubwaytogotoworkorschooleverydayasitisasafe,fastandcomfortablemeansoftransportation.ItisbecomingincreasinglyconvenienttotakethesubwayinChina.Insomecities,passengerscanaccesssubwaysimplywiththeirtransportationcardsormobilephones.Manylocalseniorcitizensalsohavefreeaccesstosubway.2018年12月大学英语四级考试真题（三）PartI Writing (30minutes)Directions:Forthispart,youareallowed30minutestowriteashortessayonthechallengesofstartingacareeraftergraduation.Youshouldwriteatleast120wordsbutnomorethan180words.PartⅡ ListeningComprehension (25minutes)特别说明：由于四级考试全国共考了两套听力，本套真题听力与前两套内容相同，只是选项顺序不同，故不再重复给出。PartⅢ ReadingComprehension (40minutes)SectionADirections:Inthissection,isapassagewithtenblanks.toselectoneforeachblankalistofchoicesgiveninabankfollowingthepassage.Readthepassagethroughcarefullybeforemakingyourchoices.EachchoiceinthebankisidentifiedbyaPleasemarkthecorrespondingletterforeachitemonAnswerSheet2withasinglelinethroughthecentre.maynotuseanyofthewordsinthebankmorethanonce.Afewmonthsago,Iwasdownwithaterriblecoldwhichendedinapersistentbadcough.Nomatterhowmanydifferent26 Itried,Istillcouldn’tgetridofthecough.Notonlydidit27myteachingbutalsomylifeasawhole.Thenonedayafterclass,astudentcameuptomeand28traditionalChinesemedicine.Fromherdescription,Chinesemedicinesoundedasifithadmagicpowerthatworkedwonders.Iwas29 becauseIknewsolittleaboutitandhavenevertrieditbefore.mycoughgotsomuch30 thatIcouldn’tsleepatnight,soIdecidedtogiveitaTheChinesedoctortookmypulseandaskedtoseemytongue,bothofwhichwerenew31tomebecausetheyarebothnon-existentinmedicine.Thenthedoctorgavemeascraping(刮)treatmentknownas‘GuaSha’.Iwasalittle32 atfirstbecauseheusedasmoothedgedtooltoscrapetheskinonmyneckandshoulders.Afewminutesthe33 strokesstartedtoproducearelievingeffectandmybodyandmindbeganto34 deeperintorelaxation.Ididn’tfeelanyimprovementinmyconditioninthefirstcoupleofdays,butafterafewmoreregularvisitstothedoctor,mycoughstartedto35 .Then,withinamatterofweeks,itwascompletelygone!H)recommendedH)recommendedO)worseG)pressuredN)trembleF)licensesM)temporaryE)lessenL)sinkD)inconvenienceK)sensitiveC)hesitantJ)scaredB)experiencesI)remediesA)deepenSectionBDirections:Inthissection,yougoingtoapassagewithtenstatementsattachedtoit.Eachstatementcontainsinformationgiveninoneoftheparagraphs.Identifytheparagraphwhichtheinformationisderived.maychooseaparagraphthanonce.EachparagraphismarkedwithaAnswerthequestionsbymarkingthecorrespondingletteronAnswerSheet2.IsitreallyOKtoeatfoodthat’sfallenonthefloor?WhenyoudropapieceoffoodontheisitreallyOKtoeatifyoupickitupwithinfiveseconds?Anurbanfoodmythcontendsthatiffoodspendsjustafewsecondsonthedirtandgermswon’thavemuchofachancetocontaminateit.Researchinmylabhasfocusedonhowfoodbecomescontaminated,andwe’vedonesomeworkonthisparticularpieceofwisdom.Whilethe“five-secondrule”mightnotseemlikethemostpressingissueforfoodscientiststogettothebottomof,it’sstillworthinvestigatingfoodmythslikethisonebecausetheyshapeourbeliefsaboutwhenfoodissafetoeat.Soisfivesecondsonthefloorthecriticalthreshold门槛)thatseparatesapieceofeatablefoodfromacaseoffoodpoisoning?abitmorecomplicatedthanthat.Itdependsonjusthowmanybacteriacanmakeitfromfloortofoodinafewsecondsandjusthowdirtytheflooris.iffoodisstillOKtoeatafterdroppedonthefloorisaprettycommonexperience.Andit’sprobablynotanewoneeither.Awell-known,butinaccurate,storyaboutJuliaChildmayhavecontributedtothisfoodmyth.Someviewersofhercookingshow,TheFrenchChef,insisttheysawChilddroplambonthefloorandpickitup,withtheadvicethatiftheywerealoneinthekitchen,theirguestswouldneverknow.Infactitwasapotatopancake,anditfellonthestovetop,notontheChildputitbackinthepan,saying,“Butyoucanalwayspickitupandifyou’realoneinthekitchen,goingtoseeit?”Butthemisrememberedstorypersists.hardertopindowntheoriginsoftheoft-quotedfive-secondrule,buta2003studyreportedthat70%ofwomenand56%ofmensurveyedwerefamiliarwiththefive-secondruleandthatwomenweremorelikelythanmentoeatfoodthathaddroppedontheSowhatdoessciencetellusaboutwhatafewmomentsonthefloormeansforthesafetyofyourfood?Theearliestresearchreportonthefive-secondruleisattributedtoJillianClarke,ahighschoolstudentparticipatinginaresearchprojectattheUniversityofIllinois.Clarkeandhercolleaguesintroducedbacteriatofloortiles(瓷砖)andthenplacedcookiesonthetilesforvaryingtimes.Theyreportedbacteriaweretransferredfromthetilestothecookieswithinfiveseconds,butdidn’treportthespecificamountofbacteriathatmadeitfromthetilestothefoodButhowmanybacteriaactuallytransferinfiveseconds?In2007,mylabatClemsonUniversitypublishedastudyintheJournalofAppliedMicrobiology.wantedtoknowifthelengthoftimefoodisincontactwithacontaminatedsurfaceaffectedtherateoftransferofbacteriatothefood.findout,weintroducedbacteriatosquaresoftile,carpetorwood.Fiveminutesafterthat,weplacedeitherbaconorbreadonthesurfacefor5,30or60seconds,andthenmeasuredthenumberofbacteriatransferredtothefood.Werepeatedthisexactprocedureafterthebacteriahadbeenonthesurfacefor2,4,8and24hours.foundthatthenumberofbacteriatransferredtoeitherkindoffooddidn’tdependmuchonhowlongthefoodwasincontactwiththecontaminatedsurface–whetherforafewsecondsorforawholeminute.Theoverallnumberofbacteriaonthesurfacematteredmore,andthisdecreasedovertimeaftertheinitialintroduction.Itlookslikeatissueislesshowlongyourfoodstaysonthefloorandmuchmorehowcontaminatedwithbacteriathatpatchoffloorhappenstobe.alsofoundthatthekindofsurfacemadeadifferenceaswell.Carpets,forinstance,seemtobeslightlybetterplacestodropyourfoodthanwoodortile.Whenacarpetwascontaminated,lessthan1%ofthebacteriaweretransferred.Butwhenthefoodwasincontactwithtileorwood,48-70%ofbacteriawere.Lastyear,astudyfromAstonUniversityintheUKusednearlyidenticalparameters(参数)toourstudyandfoundsimilarresults.Theyalsoreportedthat87%ofpeopleaskedeitherwouldeatorhadeatenfoodfallenontheShouldyoueatfoodfallenonthefloorthen?Fromafoodsafetystandpoint,ifyouhavemillionsormorebacteriaonasurface,0.1%isstillenoughtomakeyousick.Also,certaintypesofbacteriaareextremelyharmful,andittakesonlyasmallnumbertomakeyousick.Forexample,10bacteriaorlessofanespeciallydeadlystrainofbacteriacancausesevereillnessanddeathinpeoplewithcompromisedimmunesystems.ButthechanceofthesebacteriabeingonmostsurfacesisveryAndnotjustdroppingfoodonthefloorthatcanleadtobacterialcontamination.Bacteriaarecarriedbyvarious‘media’,whichcanincluderawfood,moistsurfaceswherebacteriahavebeenleft,ourhandsorskinandfromcoughingorsneezing(打喷嚏).Hands,foodsandutensils(器皿)cancarryindividualbacterialivingincommunitiescontainedwithinaprotectivefilm.Thesemicroscopiclayersofdepositscontainingbacteriaareknownasbiofilmsandtheyarefoundonmostsurfacesandobjects.Biofilmcommunitiescanharborbacteria