四级真题三Word文件下载.docx

四级真题三Word文件下载.docx

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PartIIListeningComprehension（25minutes）

说明：

由于2021年12月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，因此在本套真题中不再重复出现。

PartIIIReadingComprehension（40minutes）SectionA

Inthissection,thereisapassagewithtenblanks.Youarerequiredtoselectonewordforeachblankfromalistofchoicesgiveninawordbankfollowingthepassage.Readthepassagethroughcarefullybeforemakingyourchoices.Eachchoiceinthebankisidentifiedbyaletter.PleasemarkthecorrespondingletterforeachitemonAnswerSheet2withasinglelinethroughthecenter.Youmaynotuseanyofthewordsinthebankmorethanonce.

Afewmonthsago,Iwasdownwithaterriblecoldwhichendedinapersistentbadcough.Nomatterhowmanydifferent26Itried,Istillcouldn’tgetridofthecough.Notonlydidit27my

teachingbutalsomylifeasawhole.Thenonedayafterclass,astudentcameuptomeand28

traditionalChinesemedicine.Fromherdescription,Chinesemedicinesoundedasifithadmagicpowerthatworkedwonders.Iwas29becauseIknewsolittleaboutitandhavenevertrieditbefore.

Eventually,mycoughgotsomuch30thatIcouldn’tsleepatnight,soIdecidedtogiveitatry.The

Chinesedoctortookmypulseandaskedtoseemytongue,bothofwhichwerenew31tomebecause

theyarebothnon-existentinWesternmedicine.Thenthedoctorgavemeascraping（刮）treatment

knownas‘GuaSha’.Iwasalittle32atfirstbecauseheusedasmoothedgedtooltoscrapetheskin

onmyneckandshoulders.Afewminuteslater,the33strokesstartedtoproducearelievingeffect

andmybodyandmindbeganto34deeperintorelaxation.Ididn’tfeelanyimprovementinmy

conditioninthefirstcoupleofdays,butafterafewmoreregularvisitstothedoctor,mycoughstartedto35.Then,withinamatterofweeks,itwascompletelygone!

注意：

此部分试题请在答题卡2上作答。

SectionB

Inthissection,youaregoingtoreadapassagewithtenstatementsattachedtoit.Eachstatementcontainsinformationgiveninoneoftheparagraphs.Identifytheparagraphfromwhichtheinformationisderived.Youmaychooseaparagraphmorethanonce.Eachparagraphismarkedwithaletter.AnswerthequestionbymarkingthecorrespondingletteronAnswerSheet2.

IsitreallyOKtoeatfoodthat’sfallenonthefloor?

[A]Whenyoudropapieceoffoodonthefloor,isitreallyOKtoeatifyoupickitupwithinfive

seconds?

Anurbanfoodmythcontendsthatiffoodspendsjustafewsecondsonthefloor,dirtandgermswon’thavemuchofachancetocontaminateit.Researchinmylabhasfocusedonhowfoodbecomescontaminated,andwe’vedonesomeworkonthisparticularpieceofwisdom.

[B]Whilethe‘five-secondrule’mightnotseemlikethemostpressingissueforfoodscientiststogettothebottomof,it’sstillworthinvestigatingfoodmythslikethisonebecausetheyshapeourbeliefsaboutwhenfoodissafetoeat.

[C]Soisfivesecondsonthefloorthecriticalthreshold（门槛）thatseparatesapieceofeatablefoodfromacaseoffoodpoisoning?

It’sabitmorecomplicatedthanthat.Itdependsonjust

howmanybacteriacanmakeitfromfloortofoodinafewsecondsandjusthowdirtytheflooris.

[D]WonderingiffoodisstillOKtoeatafterit’sdroppedonthefloorisaprettycommonexperience.Andit’sprobablynotanewoneeither.Awell-known,butinaccurate,storyaboutJuliaChildmayhavecontributedtothisfoodmyth.Someviewersofhercookingshow,TheFrenchChef,insisttheysawChilddroplambonthefloorandpickitup,withtheadvicethatiftheywerealoneinthekitchen,theirguestswouldneverknow.

[E]Infactitwasapotatopancake,anditfellonthestovetop,notonthefloor.Childputitbackinthepan,saying,“Butyoucanalwayspickitupandifyou’realoneinthekitchen,who’sgoingtoseeit?

”Butthemisrememberedstorypersists.It’shardertopindowntheoriginsoftheoft-quotedfive-secondrule,buta2003studyreportedthat70%ofwomenand56%ofmensurveyedwerefamiliarwiththefive-secondruleandthatwomenweremorelikelythanmentoeatfoodthathaddroppedonthefloor.

[F]Sowhatdoessciencetellusaboutwhatafewmomentsonthefloormeansforthesafetyofyourfood?

Theearliestresearchreportonthefive-secondruleisattributedtoJillianClarke,ahighschoolstudentparticipatinginaresearchprojectattheUniversityofIllinois.Clarkeand

hercolleaguesintroducedbacteriatofloortiles（瓷砖）andthenplacedcookiesonthetilesfor

varyingtimes.Theyreportedbacteriaweretransferredfromthetilestothecookieswithinfiveseconds,butdidn’treportthespecificamountofbacteriathatmadeitfromthetilestothefood.

[G]Buthowmanybacteriaactuallytransferinfiveseconds?

In2007,mylabatClemsonUniversitypublishedastudyintheJournalofAppliedMicrobiology.Wewantedtoknowifthelengthoftimefoodisincontactwithacontaminatedsurfaceaffectedtherateoftransferofbacteriatothefood.Tofindout,weintroducedbacteriatosquaresoftile,carpetorwood.Fiveminutesafterthat,weplacedeitherbaconorbreadonthesurfacefor5,30or60seconds,andthenmeasuredthenumberofbacteriatransferredtothefood.Werepeatedthisexactprocedureafterthebacteriahadbeenonthesurfacefor2,4,8and24hours.

[H]Wefoundthatthenumberofbacteriatransferredtoeitherkindoffooddidn’tdependmuchonhowlongthefoodwasincontactwiththecontaminatedsurface—whetherforafewseconds

orforawholeminute.Theoverallnumberofbacteriaonthesurfacematteredmore,andthisdecreasedovertimeaftertheinitialintroduction.Itlookslikewhat’satissueislesshowlongyourfoodstaysonthefloorandmuchmorehowcontaminatedwithbacteriathatpatchoffloorhappenstobe.

[I]Wealsofoundthatthekindofsurfacemadeadifferenceaswell.Carpets,forinstance,seemtobeslightlybetterplacestodropyourfoodthanwoodortile.Whenacarpetwascontaminated,lessthan1%ofthebacteriaweretransferred.Butwhenthefoodwasincontactwithtileorwood,48-70%ofbacteriawere.

[J]Lastyear,astudyfromAstonUniversityintheUKusednearlyidenticalparameters（参数）toourstudyandfoundsimilarresults.Theyalsoreportedthat87%ofpeopleaskedeitherwould

eatorhadeatenfoodfallenonthefloor.

[K]Shouldyoueatfoodfallenonthefloorthen?

Fromafoodsafetystandpoint,ifyouhavemillionsormorebacteriaonasurface,0.1%isstillenoughtomakeyousick.Also,certain

typesofbacteriaareextremelyharmful,andittakesonlyasmallnumbertomakeyousick.Forexample,10bacteriaorlessofanespeciallydeadlystrainofbacteriacancausesevereillnessanddeathinpeoplewithcompromisedimmunesystems.Butthechanceofthesebacteriabeingonmostsurfacesisverylow.

[L]Andit’snotjustdroppingfoodonthefloorthatcanleadtobacterialcontamination.Bacteriaarecarriedbyvarious‘media’,whichcanincluderawfood,moistsurfaceswherebacteriahave

beenleft,ourhandsorskinandfromcoughingorsneezing（打喷嚏）.Hands,foodsandutensils

（器皿）cancarryindividualbacterialivingincommunitiescontainedwithinaprotectivefilm.Thesemicroscopiclayersofdepositscontainingbacteriaareknownasbiofilmsandtheyare

foundonmostsurfacesandobjects.Biofilmcommunitiescanharborbacterialongerandareverydifficulttoclean.Bacteriainthesecommunitiesalsohaveanenhancedresistanceto

sanitizers（清洁剂）andantibioticscomparedtobacterialivingontheirown.

[M]Sothenexttimeyouconsidereatingfallenfood,theoddsareinyourfavorthatyoucaneatitwithoutgettingsick.Butintherarechancethatthereisamicro-organismthatcanmakeyousickontheexactspotwherethefooddropped,youcanbefairlysurethatthebugisonthefoodyouareabouttoputinyourmouth.

[N]Researchorcommonsensetellsusthatthebestthingtodoiskeepyourhands,utensilsandothersurfacesclean.

36.Aresearchprojectfoundbacteriamadetheirwaytothefoodonthefloorinfiveseconds.

37.Whetherfoodiscontaminateddependsmuchonthenumberofbacteriathatgetontoit.

38.Foodcontaminationmayresultfromvariousfactorsotherthanfooddroppingonthefloor.

39.Malesarelesslikelythanfemalestoeatfoodthatmayhavebeencontaminated.

40.Theauthor’sresearchcentersaroundhowfoodgetscontaminated.

41.Keepingeverythingcleanisthebestwaytostayhealthy.

42.Chancesareyouwillnotfallsickbecauseofeatingfoodpickedupfromthefloor.

43.Foralongtimepeoplehavehadtheexperienceofdecidingwhetherornottoeatfoodpicked

upfromthefloor.

44.Somestrainsofbacteriaaresoharmfulthatatinyfewcanhavedeadlyconsequences.

45.Researchersfoundhowmanybacteriagotontothefooddidnothavemuchtodowithhowlongthefoodstayedonacontaminatedfloor.

SectionC

Thereare2passagesinthissection.Eachpassageisfollowedbysomequestionsorunfinishedstatements.ForeachofthemtherearefourchoicesmarkedA）,B）,C）andD）.YoushoulddecideonthebestchoiceandmarkthecorrespondingletteronAnswerSheet2withasinglelinethroughthecenter.

PassageOne

Questions46to50arebasedonthefollowingpassage.

Thelatestincatresearchrevealsthatthelovelyanimalseemstohaveabasicgrasponboththelawsofphysicsandtheinsandoutsofcauseandeffect.

Accordin