6月英語六級真題及答案

PartIWriting(30minutes)Directions:Forthispart,youareallowed30minutestowriteanessayon the importanee ofbuildingtrust betweenbusinessesandconsumers.Youcanciteexamples toillustrateyour views.Youshouldwriteatleast150wordsbutnomorethan200words.TheImportaneeofBuildingTrustBetween BusinessesandConsumersToday,inthecontextofthis erafeaturedbyincreasingcommercializationanddigitalization, mutually-trustedrelationsbetweenbusinessesandconsumersappeartobeparticularlyimportant.Asformebusinessesshouldtakealeadingroleinestablishing thetrustrelationship: tobehonestwiththeir consumers.Firstly,ifabusinesshasadishonestattitudetowarditscustomers,thecustomerswilllackpurchasingconfidenceinitsgoodsorservices,whichwillbringhugeeconomiclosstothebusiness.What'sworse,theadversesideeffectofsuchdishonestycanendangerthebusinessanditisimpossibletorecover.ThecollapseofSanluMilkPowderCompanyisatestamenttothis.Moreover,theincidentofpoisonousmilkhasexerteddevastatingconsequencesonthewholemilkpowdermarket.Besides,becauseoftheproliferation ofcounterfeitgoods,moreconsumersloseconfidenceindomesticproducts,andthentheyhavenoalternativebuttoresorttoforeignbrands,whichisonereasonwhycross-borderonlineshoppingisgainingmoreandmorepopularityinChina.Therefore,itishightimeforustostrengthentheimportanceofmaintainingtrustbetweenbusinessesandconsumerstopromotethehealthydevelopmenttofthewholesocialeconomy.PartIIListeningComprehension(30minutes)PartIIListeningComprehension(30minutes)說明：由于2018年6月六級考試全國共考了兩套聽力，本套真題聽力與前 2套內(nèi)容相同，只是選項(xiàng)順序不同，因此在本套真題中不再重復(fù)出現(xiàn)。PartIII ReadingComprehension(40minutes)SectionADirections:Inthissection,thereisapassagewithtenblanks.Youarerequiredtoselectonewordforeachblankfromalistofchoicesgiveninawordbankfollowingthepassage.Readthepassagethroughcarefullybeforemakingyourchoices.Eachchoiceinthebankisidentifiedbyaletter.PleasemarkthecorrespondingletterforeachitemonAnswerSheet2withasinglelinethroughthecenter.Youmaynotuseanyofthewordsinthebankmorethanonce.DidSarahJosephaHalewrite"Mary'sLittleLamb,"theeternalnurseryrhyme(兒歌)aboutagirl namedMarywithastubbornlamb?Thisisstilldisputed,butit'sclearthatthewoman26forwritingitwasoneofAmerica'smostfascinating27.Inhonorofthepoem'spublicationonMay24,1830,here'smoreaboutthe28author'slife.Halewasn'tjustawriter,shewasalsoa29socialadvocate,andshewasparticularly30withanidealNewEngland,whichsheassociatedwithabundantThanksgivingmealsthatsheclaimedhad"adeepmoralinfluenee."Shebegananationwide31tohaveanationalholidaydeclaredthatwouldbringfamiliestogetherwhilecelebratingthe32festivals.In1863,after17yearsofadvocacyincludingletterstofivepresidents, Halegotit. PresidentAbrahamLincoln,duringtheCivilWar,issueda33setting asidethelastThursdayinNovemberfortheholiday.Thetrueauthorshipof"Mary'sLittleLamb"isdisputed.AccordingtotheNewEnglandHistoricalSociety,Halewroteonlypartofthepoem,butclaimedauthorship.Regardlessoftheauthor,itseemsthatthepoemwas34byarealevent.WhenyoungMarySawyerwasfollowedtoschoolbyalambin1816,itcausedsomeproblems.AbystandernamedJohnRoulstonewroteapoemabouttheevent,then,atsomepoint,Haleherselfseemstohavehelpedwriteit.However,ifa1916piecebyhergreat-nieceistobetrusted,Haleclaimedforthe35ofherlifethat"someotherpeoplepretendedthatsomeoneelsewrotethepoem".campaign E)fiercecareer F)inspiredcharacters G)latter

proclamationJ) rectifiedK) reputedM) supposedN) traditionalM) supposedN) traditionalO) versatileSectionBDirections:Inthissection,youaregoingtoreadapassagewithtenstatementsattachedtoit.Eachstatementcontainsinformationgiveninoneoftheparagraphs.Identifytheparagraphfromwhichtheinformationisderived.Youmaychooseaparagraphmorethanonce.Eachparagraphismarkedwithaletter.AnswerthequestionsbymarkingthecorrespondingletteronAnswerSheet2.GrowPlantsWithoutWaterA） Eversincehumanitybegantofarmourownfood,we 'vefacedtheunpredictablerainthatisbothfriendandenemy.Itcomesandgoeswithoutmuchwarning,andafieldoflush（ 茂盛的）leafygreensoneyearcandryupandblowawaythenext.Foodsecurityandfortunesdependonsufficientrain,andnowheremoresothaninAfrica,where96%offarmlanddependsonraininsteadoftheirrigationcommoninmoredevelopedplaces.Ithasconsequences:SouthAfrica'songoingdrought—theworstinthreedecades—willcostatleastaquarterofitscorncropthisyear.B） BiologistJillFarrantoftheUniversityofCapeTowninSouthAfricasaysthatnaturehasplentyofanswersforpeoplewhowanttogrowcropsinplaceswithunpredictablerainfall.Sheishardatworkfindingawaytotaketraitsfromrarewildplantsthatadapttoextremedryweatherandusetheminfoodcrops.Astheearth'sclimatechangesandrainfallbecomesevenlesspredictableinsomeplaces,thoseanswerswillgrowevenmorevaluable."Thetypeoffarmingrmaimingforisliterallysothatpeoplecansurviveasit'sgoingtogetmoreandmoredry,"Farrantsays.C） Extremeconditionsproduceextremelytoughplants.IntherustyreddesertsofSouthAfrica,steep-sidedrockyhillscalledinselbergsrearupfromtheplainslikethebonesoftheearth.Thehillsareremnantsofanearliergeologicalera,scrapedbareofmostsoilandexposedtotheelements.Yetontheseandsimilarformationsindesertsaroundtheworld,afewfierceplantshaveadaptedtoendureunderever-changingconditions.D） Farrantcallsthemresurrectionplants（復(fù)蘇植物）.Duringmonthswithoutwaterunderaharshsun,theywither,shrinkandcontractuntiltheylooklikeapileofdeadgrayleaves.Butrainfallcanrevivetheminamatterofhours.Hertime-lapse（間歇性扌白攝的）videosoftherevivalslooklikesomeoneplayingatapeoftheplant'sdeathinreverse.E） Thebigdiffereneebetween"drought-tolerant"plantsandthesetoughplants:metabolism.Manydifferentkindsofplantshavedevelopedtacticstoweatherdryspells.Someplantsstorereservesofwatertoseethemthroughadrought;otherssendrootsdeepdowntosubsurfacewatersupplies.Butonce

theseplantsuseuptheirstoredreserveortapouttheundergroundsupply,theyceasegrowingandstarttodie.Theymaybeabletohandleadroughtofsomelength,andmanypeopleusetheterm"droughttolerant"todescribesuchplants,buttheyneveractuallystopneedingtoconsumewater,soFarrantpreferstocallthemdroughtresistant.Resurrection plants, definedasthosecapableofrecovering fromholdinglessthangramsofwaterpergramofdrymass,aredifferent.Theylackwater-storingstructures,andtheirexisteneeonrockfacespreventsthemfromtappinggroundwater,sotheyhaveinsteaddevelopedtheability tochangetheirmetabolism.Whentheydetectanextendeddryperiod,theydiverttheirmetabolisms,producingsugarsandcertainstress-associatedproteinsandothermaterialsintheirtissues.Astheplantdries,theseresourcestakeonfirstthepropertiesofhoney,thenrubber,andfinallyenteraglass-likestatethatis"themoststablestatethattheplantcanmaintain，”Farrantsays.Thatslowstheplant'smetabolismandprotectsitsdried-outtissues.Theplantsalsochangeshape,shrinkingtominimizethesurfaceareathroughwhichtheirremainingwatermightevaporate.Theycanrecoverfrommonthsandyearswithoutwater,dependingonthespecies.Whatelsecandothisdry-out-and-revivetrick?Seeds —almostallofthem.Atthestartofhercareer,Farrantstudied"recalcitrantseeds( 頑拗性種子),"suchasavocados,coffeeandlychee.Whiletasty,suchseedsaredelicate—theycannotbudandgrowiftheydryout(asyoumayknowifyou'veevertriedtogrowatreefromanavocadopit).Intheseedworld,thatmakesthemrare,becausemostseedsfromfloweringplantsarequiterobust.Mostseedscanwaitoutthedry,unwelcomingseasonsuntilconditionsarerightandtheysprout(發(fā)芽).Yetoncetheystartgrowing,suchplantsseemnottoretaintheabilitytohitthepausebuttononmetabolismintheirstemsorleaves.AftercompletingherPh.D.onseeds,Farrantbeganinvestigatingwhetheritmightbepossibletoisolatethepropertiesthatmakemostseedssoresilient (迅速恢復(fù)活力的)andtransferthemtootherplanttissues. WhatFarrantandothershavefoundoverthepasttwodecadesisthattherearemanygenesinvolvedinresurrectionplants'responsetodryness.Manyofthemarethesamethatregulatehowseedsbecomedryness-tolerantwhilestillattachedtotheirparentplants.Nowtheyaretryingtofigureoutwhatmolecularsignalingprocessesactivatethoseseed-buildinggenesinresurrectionplants —andhowtoreproducethemincrops."Mostgenesareregulatedbyamastersetofgenes,"Farrantsays."We'relookingatgenepromotersandwhatwouldbetheirmasterswitch."tryingthreemethodsof breeding,"FarrantOnceFarrantandhercolleaguesfeeltheyhaveabettersenseofwhichswitchestothrow,theywillhavetofindthebestwaytodosoinusefulcrops."I'mtryingthreemethodsof breeding,"Farrantsays:conventional,geneticmodificationandgeneediting.Shesayssheisawarethatpientyofpeopledonotwanttoeatgeneticallymodifiedcrops,butsheispushingaheadwitheveryavailabletooluntiloneworks.Farmersandconsumersalikecanchoosewhetherornottousewhicheverversionprevails :"I'mgivingpeopleanoption."Farrantandothersintheresurrection businessgottogetherlastyeartodiscussthebestspeciesofresurrectionplanttouseasalabmodel.Justlikemedicalresearchersuseratstotestideasforhumanmedicaltreatments,botanistsuseplantsthatarerelativelyeasytogrowinalaborgreenhousesettingtotesttheirideasforrelatedspecies.TheQueenslandrockvioletisoneofthebeststudiedresurrectionplantssofar,withadraftgenome( 基因圖譜)publishedlastyearbyaChineseteam.Alsolastyear,Farrantandcolleaguespublishedadetailedmolecularstudyofanothercandidate,Xerophytaviscosa,atough-as-nailSouthAfricanplantwithlily-likeflowers,andshesaysthatagenomeisontheway.Oneorbothofthesemodelswillhelpresearcherstesttheirideas —sofarmostlydoneinthelab—ontestplots.Understandingthebasicscieneefirstiskey.Therearegoodreasonswhycropplantsdonotusedrynessdefensesalready.Forinstanee, there'sahighenergycostinswitchingfromaregularmetabolismtoanalmost-no-watermetabolism.Itwillalsobenecessarytounderstandwhatsortofyieldfarmersmightexpectandtoestablishtheplant'ssafety."Theyieldisnevergoingtobehigh,"Farrantsays,sotheseplantswillbetargetednotatIowafarmerstryingtosqueezemorecashoutofhigh-yieldfields,butsubsisteneefarmerswhoneedhelptosurviveadroughtlikethepresentoneinSouthAfrica."Myvisionisforthesubsisteneefarmer,"Farrantsays."I'mtargetingcropsthatareofAfricanvalue."Thereareacoupleofplantstoughandadaptableenoughtosurviveonbarerockyhillsandindeserts.Farrantistryingtoisolategenesinresurrectionplantsandreproducethemincrops.FarmersinSouthAfricaaremoreatthemercyofnature,especiallyinconsistentrainfall.Resurrectioncropsaremostlikelytobethechoiceofsubsisteneefarmers.Eventhoughmanyplantshavedevelopedvarioustacticstocopewithdryweather,theycannotsurviveaproIongeddrought.Despiteconsumerresistanee,researchersarepushingaheadwithgeneticmodificationofcrops.Mostseedscanpullthroughdryspellsandbegingrowingwhenconditionsareripe, butoncethisprocessstarts,itcannotbeheldback.Farrantisworkinghardtocultivatefoodcropsthatcansurviveextremedrynessbystudyingthetraitsofrarewildplants.Byadjusting theirmetabolism,resurrectionplantscanrecoverfromanextendedperiodofdrought.Resurrectionplantscancomebacktolifeinashorttimeafterarainfall.SectionCDirections:Thereare2passagesinthissection. Eachpassageisfollowedbysomequestionsorunfinishedstatements.ForeachofthemtherearefourchoicesmarkedA),B),C)andD).YoushoulddecideonthebestchoiceandmarkthecorrespondingletteronAnswerSheet2withasinglelinethroughthecenter.PassageOneQuestions46to50arebasedonthefollowingpassage.Humanmemoryisnotoriously unreliable.Evenpeoplewiththesharpestfacial-recognition skillscanonlyremembersomuch.It'stoughtoquantifyhowgoodapersonisatremembering.Noonereallyknowshowmanydifferentfacessomeonecanrecall,forexample,butvariousestimatestendtohoverinthethousands ——basedonthenumberofacquaintancesapersonmighthave.Machinesaren'tlimitedthisway.Givetherightcomputeramassivedatabaseoffaces,anditcanprocesswhatitsees—thenrecognizeafaceit'stoldtofind—withremarkablespeedandprecision.Thisskilliswhatsupportstheenormouspromiseoffacial-recognitionsoftwareinthe21stcentury.It'salsowhatmakescontemporarysurveillaneesystemssoscary.Thethingis,machinesstillhavelimitationswhenitcomestofacialrecognition.Andscientistsareonlyjustbeginningtounderstandwhatthoseconstraintsare.Tobegintofigureouthowcomputersarestruggling,researchersattheUniversityofWashingtoncreatedamassivedatabaseoffaces —theycallitMegaFace—andtestedavarietyoffacial-recognitionalgorithms( 算法)astheyscaledupincomplexity.Theideawastotestthemachinesonadatabasethatincludedupto1milliondifferentimagesofnearly700,000differentpeople —andnotjustalargedatabasefeaturingarelativelysmallnumberofdifferentfaces,moreconsistentwithwhat'sbeenusedinotherresearch.Asthedatabasesgrew,machineaccuracydippedacrosstheboard.Algorithmsthatwereright95%ofthetimewhentheyweredealingwitha13,000-imagedatabase,forexample,wereaccurateabout70%ofthetimewhenconfrontedwith1millionimages.That'sstillprettygood,saysoneoftheresearchers,IraKemelmacher-Shlizerman."Muchbetterthanweexpected,"shesaid.

Machinesalsohaddifficultyadjustingforpeoplewholookalotalike—eitherdoppelgangers( 長—eitherdoppelgangers( 長whoappearedindifferentphotosatdifferentagesorindifferentlighting,whomthemachinewouldincorrectlyviewasseparatepeople."Oncewescaleup,algorithmsmustbesensitivetotinychangesinidentitiesandatthesametimeinvarianttolighting,pose,age,"Kemelmacher-Shlizermansaid.Thetroubleis,formanyoftheresearcherswho'dliketodesignsystemstoaddressthesechallenges,massivedatasetsforexperimentationjustdon'texist —atleast,notinformatsthatareaccessibletoacademicresearchers.TrainingsetsliketheonesGoogleandFacebookhaveareprivate.Therearenopublicdatabasesthatcontainmillionsoffaces.MegaFace'screatorssayit'sthelargestpubliclyavailablefacial-recognitiondatasetoutthere."Anultimatefacerecognitionalgorithmshouldperformwithbillionsofpeopleinadataset,"theresearcherswrote.Comparedwithhumanmemory,machinescan .identifyhumanfacesmoreefficientlytellafriendfromamereacquaintancestoreanunlimitednumberofhumanfacesperceiveimagesinvisibletothehumaneyeWhydidresearcherscreateMegaFace?Toenlargethevolumeofthefacial-recognitiondatabase.Toincreasethevarietyoffacial-recognitionsoftware.Tounderstandcomputers'problemswithfacialrecognition.Toreducethecomplexityoffacial-recognitionalgorithms.Whatdoesthepassagesayaboutmachineaccuracy?Itfallsshortofresearchers'expectations.Itimproveswithaddedcomputingpower.Itvariesgreatlywithdifferentalgorithms.Itdecreasesasthedatabasesizeincreases.Whatissaidtobeashortcoming-offacial-recognitionmachines?Theycannoteasilytellapartpeoplewithnear-identicalappearances.Theyhavedifficultyidentifyingchangesinfacialexpressions.Theyarenotsensitivetominutechangesinpeople'smood.Theyhaveproblemsdistinguishingpeopleofthesameage.Whatisthedifficultyconfrontingresearchersoffacial-recognitionmachines?Nocomputerisyetabletohandlehugedatasetsofhumanfaces.Theredonotexistpublicdatabaseswithsufficientfacesamples.Therearenoappropriatealgorithmstoprocessthefacesamples.Theyhavetroubleconvertingfacedatasetsintotherightformat.PassageTwoQuestions51to55arebasedonthefollowingpassage.There're currentlymillionstudentsinAmerica,andmanywillbefundingtheircollegeonborrowedmoney.Giventhatthere'snowover$trillioninstudentloansonthebooks,it'sprettyclearthatmanystudentsarefarfromsensible.Theaveragestudent'sdebtupongraduationnowapproaches$40,000,andascollegebecomesevermoreexpensive,callstomakeit"free"aremultiplying.EvenHillaryClintonsaysthatwhenitcomestocollege,"Costswon'tbeabarrier."Buttheonlywaycollegecouldbefreeisifthefacultyandstaffdonatedtheirtime,thebuildingsrequirednomaintenance,andcampusesrequirednoutilities.Aslongasit'simpossibletoproducesomethingfromnothing,costsareabsolutelyabarrier.Theactualquestionwedebateiswhoshouldpayforpeopletogotocollege.Iftaxpayersaretobearthecostofforgivingstudentloans,shouldn'ttheyhaveasayinhowtheirmoneyisused?Atleasttaxpayersshouldbeabletodecidewhatstudentswillstudyonthepublicdime.Ifwe'regoingtoforcetaxpayerstofootthebillforcollegedegrees,studentsshouldonlystudythosesubjectsthat'reofgreatestbenefittotaxpayers.Afterall,studentsmakingtheirownchoicesinthisrespectiswhatcausedtheprobleminthefirstplace.Wesimplydon'tneedmorepoetry,genderstudies,orsociologymajors.Howdoweknowwhichsubjectsbenefitsociety?Easy.Averagestartingsalariesgiveaclearindicationofwhattypeoftrainingsocietyneedsitsnewworkerstohave.Certainly,there'rebenefitstoacollegemajorbeyondthejobastudentcanperform.Butifwe'retalkingaboutthebenefitstosociety,theonlythingthatmattersiswhatthemajorenablesthestudenttoproduceforsociety.Andthevalueofwhatthestudentcanproduceisreflectedinthewageemployersarewillingtopaythestudenttoproduceit.Alowwageforelementaryschoolteachers,however,doesn'tmeanelementaryeducationisn'timportant.Itsimplymeansthere'retoomanyelementaryschoolteachersalready.Meanwhile,there'refewwho'rewillingandabletoperformjobsrequiringapetroleumengineeringmajor,sothevalueofonemoreofthosepeopleisveryhigh.Sowecanhavetaxpayerspickupstudents'tuitioninexchangefordictatingwhatthosestudentswillstudy.Orwecanallowstudentsbothtochoosetheirmajorsandpayfortheireducationthemselves.Butintheend,oneoftwothingsistrue:Eitheracollegemajorisworthitscostoritisn't.Ifyes,taxpayerfinancingisn't needed.Ifnot,taxpayerfinancing isn't desirable.Eitherway,taxpayershavenobusinesspayingforstudents'collegeeducation.Whatdoestheauthorthinkofcollegestudentsfundingtheireducationthroughloans?Theyonlyexpecttogethugereturns.Theyareactinginanirrationalway.Theybenefit