2018年6月英语六级考试真题第2套

SectionDirections:Inthissection,youwillheartwopassages.Attheendofeachpassage,youwillhearthreeorfourquestions.Boththepassageandthequestionswillbespokenonlyonce.Afteryouhearaquestion,youmustchoosethebestanswerfromthefourchoicesmarkedA),B),C)andD).ThenmarkthecorrespondingletteronAnswerSheet1withasinglelinethroughthecentre.Questions9to11arebasedonthepassageyouhavejustA).Stretchesof B).TypicalEgyptiananimalC).Tombsofancient D).RuinsleftbydevastatingA).ItprovideshabitatsformoreprimitiveItishardlyassociatedwithgreatIthasnotyetbeenfullyexploredandItgatherswaterfrommanytropical A).Itcarriesaboutonefifthoftheword'freshIthasnumeroushumansettlementsalongitsItissecondonlytotheMississippiRiverinItisaslongastheNileandtheYangtzeQuestions12to15arebasedonthepassageyouhavejustA).LivingalifeinthefastlaneleadstoWearealwaysinarushtodovariousThesearchfortranquility eaAllofusactuallyyearnforaslowandcalmlifeA).Shehadtroublebalancingfamilyand B).Sheenjoyedthevarioussocial D).Shespentallherleisuretimewriting ingawareofherC).Thefatiguefromlivingafast-paced D).Readingabookaboutslowing B).Shecameto C).Shelearntousemorepolite SectionDirections:Inthissection,youwillhearthreerecordingsoflecturesortalksfollowedbythreeorfourquestions.Therecordingswillbeyedonlyonce.Afteryouhearaquestion,youmustchoosethebestanswerfromthefourchoicesmarkedA),B),C)andD).ThenmarkthecorrespondingletteronAnswerSheet1withasinglelinethroughthecentre.Questions16to18arebasedontherecordingyouhavejust B).TheycontributetoaC).Theyposeathreattothelocal A).Theirclassificationsare B).Their ctionsarehardtoC).Theirdefinitionsare D).TheirdistinctionsareA).OnlyafewofthemcauseproblemstoTheymayturntobenefitthelocalFewofthemcansurviveintheirnewOnly10percentofthemcanbeQuestions19to21arebasedontherecordingyouhavejustA).Respecttheirtraditional B).AttendtheirbusinessC).Researchtheirspecific D).AdopttherightbusinessA).ShowingthemyourGivingthemgiftsofgreatDrinkingalcoholoncertaindaysofaClickingyourfingersloudlyintheirA).Theyareveryeasyto B).Theyhaveastrongsense D).Theyhaveabreakfrom2:00to5:30Questions22to25arebasedontherecordingyouhavejustHetookoverthesalesdepartmentofReader'sItsarticlesshouldbeshortandA).HeknewhowtomakethemagazineA).Itcarriedmanymore B).GeorgeGrunejoineditasanad Part Reading SectionDirections:Inthissection,thereisapassagewithtenblanks.Youarerequiredtoselectonewordforeachblankfromalistofchoicesgiveninawordbankfollowingthepassage.Readthepassagethroughcarefullybeforemakingyourchoices.Eachchoiceinthebankisidentifiedbyaletter.PleasemarkthecorrespondingletterforeachitemonAnswerSheet2withasinglelinethroughthecentre.Youmaynotuseanyofthewordsinthebankmorethanonce.Questions26to35arebasedonthefollowingDidSarahJosephaHalewrite“MarysLittleLamb,theeternalnurseryrhymeaboutagirlnamedMarywithastubbornlambThisisstilldisputebutit’sclearthatthewoman26forwritingitwasoneofAmerica'smostfascinating27_.InhonorofthepoemspublicationonMay24，1830here’smoreaboutthe28author'sHalewasn’tjustawriter,shewasalsoa29socialadvocate,andshewasparticularly30_withanidealNewbegananationwide31tohaveanationalholidaydeclaredthatwouldbringfamiliestogetherwhile AbrahamLincoln,duringtheCivilWar,issueda theholiday.

settingasidethelastThursdayinNovemberwroteonlyonepartofthepoem,butclaimedauthorship.Regardlessoftheauthor,itseemsthatthepoemwas34byarealevent.WhenyoungMarySawyerwasfollowedtoschoolbyalambin1816,itcausedsomeherlifethat“Someotherpeoplepretendedthatsomeoneelsewrotethepoem”.

35nC).E).G).I).K).M).O).B).F).J).L).N).SectionDirections:Inthissection,youaregoingtoreadapassagewithtenstatementsattachedtoit.Eachstatementcontainsinformationgiveninoneoftheparagraphs.Identifytheparagraphfromwhichtheinformationisderived.Youmaychooseaparagraphmorethanonce.Eachparagraphismarkedwithaletter.AnswerthequestionsbymarkingthecorrespondingletteronAnswerSheet2.GrowntsWithout[A].Eversincehumanitybegantofarmourownfood,we'vefacedtheunpredictablerainthatisbothfriendandenemy.Itcomesandgoeswithoutmuchwarning,andafieldoflush(茂盛的)leafygreensoneyearcandryupandblowawaythenext.Foodsecurityandfortunesdependonsufficientrain,andnowheremoresothaninAfrica,where96%offarmlanddependsonraininsteadoftheirrigationcommoninmoredevelopedces.Ithasconsequences:SouthAfrica'songoingdrought—theworstinthreedecades—willcostatleastaquarterof itscomcropthisyear.[B].BiologistJillFarrantoftheUniversityofCapeTowninSouthAfricasaysthatnaturehasplentyofanswersforpeoplewhowanttogrowcropsinceswithunpredictablerainfall.Sheishardatworkfindingawaytotaketraitsfromrarewildntsthatadapttoextremedryweatherandusetheminfoodcrops.Astheearth'sclimatechangesandrainfall esevenlesspredictableinsomeces,thoseanswerswillgrowevenmorevaluable."ThetypeoffarmingI'maimingforislillysothatpeoplecansurviveasit'sgoingtogetmoreandmoredry,"Farrantsays.[C].Extremeconditionsproduceextremelytoughnts.IntherustyreddesertsofSouthAfrica,steep-sidedrockyhillscalledinselbergsrearupfromtheinslikethebonesoftheearth.Thehillsareremnantsofanearliergeologicalera,scrapedbareofmostsoilandexposedtotheelements.Yetontheseandsimilarformationsindesertsaroundtheworld,afewfiercentshaveadaptedtoendureunderever-changing[D].Farrantcallsthemresurrectionnts(复苏植物).DuringmonthswithoutwaterunderaharshTheywither,shrinkandcontractuntiltheylooklikeapileofdeadgrayleaves.Butrainfallcanrevivetheminamatterofhours.Hertime-lapse间歇性拍摄的)softherevivalslooklikeyingatapeofthent'sdeathin[E].Thebigdifferencebetween"drought-tolerant"ntsandthesetoughnts:metabolism.Manydifferentkindsofntshavedevelopedtacticstoweatherdryspells.Somentsstorereservesofwatertoseethemthroughadrought;otherssendrootsdeepdowntosubsurfacewaters.Butoncethesentsuseuptheirstoredreserveortapouttheundergroundsupply,theyceasegrowingandstarttodie.Theymaybeabletohandleadroughtofsomelength,andmanypeopleusetheterm"droughttolerant"todescribesuchnts,buttheyneveractuallystopneedingtoconsumewater,soFarrantpreferstocallthemdrought[F].Resurrectionnts,definedasthosecapableofrecoveringfromholdinglessthan0.1gramsofwaterpergramofdrymass,aredifferent.Theylackwater-storingstructures,andtheirexistenceonrockfacespreventsthemfromtapgroundwater,sotheyhaveinsteaddevelopedtheabilitytochangetheirmetabolism.Whentheydetectanextendeddryperiod,theydiverttheirmetabolisms,producingsugarsandcertainstress-associatedproteinsandothermaterialsintheirtissues.Asthentdries,theseresourcestakeonfirstthepropertiesofhoney,thenrubber,andfinallyenteraglass-likestatethatis"themoststablestatethatthentcanmaintain,"Farrantsays.Thatslowsthent'smetabolismandprotectsitsdried-outtissues.Thentsalsochangeshape,shrinkingtominimizethesurfaceareathroughwhichtheirremainingwatermightevaporate.Theycanrecoverfrommonthsandyearswithoutwater,dependingonthespecies.[G].Whatelsecandothisdry-out-and-revivetrick?Seeds-almostallofthem.Atthestartofhercareer,Farrantstudied.recalcitrantseeds(执拗性),"suchasavocados,coffeeandlychee.Whiletasty,suchseedsaredelicate--theycannotbudandgrowiftheydryout(asyoumayknowifyou've triedtogrowatreefromanavocadopit).Intheseedworld,thatmakesthemrare,becausemostseedsfromfloweringntsarequiterobust.Mostseedscanwaitoutthedry, ingseasonsuntilconditionsarerightandtheysprout(发芽).Yetoncetheystartgrowing,suchntsseemnottoretaintheabilitytohitthepausebuttononmetabolismintheirstemsor [H].AftercompletingherPh.D.onseeds,Farrantbeganinvestigatingwhetheritmightbepossibletoisolatethepropertiesthatmakemostseedssoresilient(迅速恢力的)andtransferthemtoothernttissues.WhatFarrantandothershavefoundoverthepasttwodecadesisthattherearemanygenesinvolvedinresurrectionnts'responsetodryness.Manyofthemarethesamethatregulatehowseeds edryness-tolerantwhilestillattachedtotheirparentnts.Nowtheyaretryingtofigureoutwhatmolecularsignalingprocessesactivatethoseseed-buildinggenesinresurrectionnts—andhowtoreproducethemincrops."Mostgenesareregulatedbyamasterset ofgenes,"Farrantsays."We'relookingatgenepromotersandwhatwouldbe theirmasterswitch." OnceFarrantandhercolleaguesfeeltheyhaveabettersenseofwhichswitchestothrow,theywillhavetofindthebestwaytodosoinusefulcrops."I'mtryingthreemethodsofbreeding,"Farrantsays:conventional,geneticmodificationaridgeneediting.Shesayssheisawarethatplentyofpeopledonotwanttoeatgeneticallymodifiedcrops,butsheispushingaheadwitheveryavailabletooluntiloneworks.Farmersandconsumersalikecanchoosewhetherornottousewhicheverversionprevails:"I'mgivingpeopleanoption."[JFarrantandothersintheresurrectionbusinessgottogetherlastyeartodiscussthebestspeciesofresurrectionnttouseasalabmodel.Justlikemedicalresearchersuseratstotestideasforhumanmedicaltreatments,botanistsusentsthatarerelativelyeasytogrowinalaborgreenhousesettingtotesttheirideasforrelatedspecies.TheQueenslandrockvioletisoneof resurrectionntssofar,withadraftgenome(图谱)publishedlastyearbyateam.Alsolastyear,Farrantandcolleaguespublishedadetailedmolecularstudyofanothercandidate,Xerophytaviscosa,atough-as-nailsouthAfricanntwithlily-likeflowers,andshesaysthatagenomeisontheway.oneorbothofthesemodelswillhelpresearcherstesttheirideas—sofarmostlydoneinthelab—ontestplots.[K].Understandingthebasicsciencefirstiskey.Therearegoodreasonswhycropntsdonotusedrynessdefensesalready.Forinstance,there'sahighenergycostinswitchingfromaregularmetabolismtoanalmost-no-watermetabolism.Itwillalsobenecessarytounderstandwhatsortofyieldfarmersmightexpectandtoestablishthent'ssafety."Theyieldisnevergoingtobehigh,"Farrantsays,sothesentswillbetargetednotatIowafarmerstryingtosqueezemorecashoutofhigh-yieldfields,butsubsistencefarmerswhoneedhelptosurviveadroughtlikethepresentoneinSouthAfrica."Myvisionisforthesubsistencefarmer,"Farrantsays."I'mtargetingcropsthatareofAfricanvalue.".ThereareacoupleofntstoughandadaptableenoughtosurviveonbarerockyhillsandinFarrantistryingtoisolategenesinresurrectionntsandreproducetheminFarmersin Africaaremoreatthemercyofnature,especiallyinconsistentResurrectioncropsaremostlikelytobethechoiceof Eventhoughmanyntshavedevelopedvarioustacticstocopewithdryweather,theycannotsurviveaprolongeddrought.Despite ,researchersarepushingaheadwithgeneticmodificationofMostseedscanpullthroughdryspellsandbegingrowingwhenconditionsareripe,butoncethisprocessstarts,itcannotbeheldback.Farrantisworkinghardtocultivatefoodcropsthatcallsurviveextremedrynessbystudyingthetraitsofrarewildnts.Byadjustingtheirmetabolism,resurrectionntscan fromanextendedperiodofResurrectionntscancomebacktolifeinashorttimeafter SectionDirections：Thereare2passagesinthissection.Eachpassageisfollowedbysomequestionsorunfinishedstatements.ForeachofthemtherearefourchoicesmarkedA),B),C)andD).YoushoulddecideonthebestchoiceandmarkthecorrespondingletteronAnswerSheet2withasinglelinethroughthecentrepassageQuestions46to50arebasedonthefollowingHumanmemoryisnotoriouslyunreliable.Evenpeoplewiththesharpestfacial-recognitionskillscanonlyremembersomuch.It'stoughtofyhowgoodaisatremembering.Noonereallyknowshowmanydifferentfacessomeonecanrecall,forexample,butvariousestimatestendtohoverinthethousands-basedonthenumberofacquaintancesamighthave.Machinesaren'tlimitedthisway,Givetherightcomputeramassivedatabaseoffaces,anditcanprocesswhatitsees-thenrecognizeafaceit'stoldtofind-withremarkablespeedandprecision.Thisskilliswhatsupportstheenormouspromiseoffacial-recognitionsoftwareinthe2lstcentury.It'salsowhatmakescontemporarysurveillancesystemssoscary.Thethingis,machinesstillhavelimitationswhenitcomestofacialrecognition.Andscientistsareonlyjustbeginningtounderstandwhatthoseconstraintsare.TobegintofigureouthowcomputersarestrugglingresearchersattheUniversityofWashingtoncreatedamassivedatabaseoffacestheycallitMegaFaceandtestedavarietyoffacial-recognitionalgorithmsasscaledupincomplexity.Theideawastotestthemachinesonadatabasethatincludedupto1milliondifferentimagesofnearly700,000differentpeople-andnotjustalargedatabasefeaturingarelativelysmallnumberofdifferentfaces,moreconsistentwithwhat'sbeenusedinotherresearch.Asthedatabasesgrew,machineaccuracydippedacrosstheboard.Algorithmsthatwereright95%ofthetimewhentheyweredealingwitha13,000-imagedatabase,forexample,wereaccurateabout70%ofthetimewhenconfrontedwith1millionimages.That'sstillprettygood,saysoneoftheresearchers,IraKemelmacher-Shlizerman."Muchbetterthanweexpected,"shesaid.Machinesalsohaddifficultyadjustingforpeoplewholookalotalike-eitherdoppelgangers(长相极相似的人),whomthemachinewouldhavetroubleidentifyingastwoseparatepeople,orthewhoappearedindifferentphotosatdifferentagesorindifferentlighting,whommachinewouldincorrectlyviewasseparate"Oncewescaleup,algorithmsmustbesensitivetotinychangesinidentitiesandatthesametimeinvarianttolighting,pose,age,"Kemelmacher-Shlizermansaid.Thetroubleis,formanyoftheresearcherswho'dliketodesignsystemstoaddressthesechallenges,massivedatasetsforexperimentationjustdon'texist--atleast,notinformatsthatareaccessibletoacademicresearchers.Trainingsetsliketheonesandhaveareprivate.Therearenopublicdatabasesthatcontainmillionsoffaces.MegaFace'screatorssayit'sthelargestpubliclyavailablefacial-recognitiondatasetoutthere.“Anultimatefacerecognitionalgorithmshouldperformwithbillionsofpeopleinadataset,”theresearcherswrote.paredwithhumanmemory,machines identifyhumanfacesmorelafriendfromamerestoreanunlimitednumberofhumanperceiveimagesinvisibletothehumanWhydidresearcherscreateToenlargethevolumeofthefacial-recognitionToincreasethevarietyoffacial-recognitionTounderstandcomputers'problemswithfacialToreducethecomplexityoffacial-recognitionWhatdoesthepassagesayaboutmachineItfallsshortofresearchers'ItimproveswithaddedcomputingItvariesgreatlywithdifferentItdecreasesasthedatabasesizeWhatissaidtobe ingoffacial-recognitionTheycannot lapartpeoplewithnear-identicalTheyhavedifficultyidentifyingchangesinfacialTheyarenotsensitivetominutechangesinpeople'sTheyhaveproblemsdistinguishingpeopleofthesameWhatisthedifficultyconfrontingresearchersoffacial-NocomputerisyetabletohandlehugedatasetsofhumanTheredonotexistpublicdatabaseswithsufficientfaceTherearenoappropriatealgorithmstoprocessthefaceTheyhavetroubleconvertingfacedatasetsintotherightPassageQuestions51to55arebasedonthefollowingThere’recurrently21.5millionstudentsinAmerica,andmanywillbefundingtheircollegeonborrowedmoney.Giventhatthere'snowover$1.3trillioninstudentloansonthebooks,it'sprettyclearthatmanystudentsarefarfromsensible.Theaveragestudent'sdebtupongraduationnowapproaches$40,000,andascollege esevermoreexpensive,callstomakeit""aremultiplying.EvenHillaryClintonsaysthatwhenitcomestocollege,"Costswon'tbeabarrier."Buttheonlywaycollegecouldbeisifthefacultyandstaffdonatedtheirtime,thebuildingsrequirednomaintenance,andcampusesrequirednoutilities.Aslongasit'simpossibletoproducesomethingfromnothingcostsareabsoluyabarrier.Theactualquestionwedebateiswhoshouldpayforpeopletogotocollege.Iftaxpayersaretobearthecostofforgivingstudentloans,shouldn'ttheyhaveasayinhowtheirmoneyisused?Atleasttaxpayersshouldbeabletodecidewhatstudentswillstudyonthepublicdime.Ifwe'regoingtotaxpayerstofootthebillforcollegedegrees,studentsshouldonlystudythosesubjectsthat’reofgreatestbenefittotaxpayers.Afterall,studentsmakingtheirownchoicesinthisrespectiswhatcausedtheprobleminthefirstce.Wesimplydon'tneedmorepoetry,genderstudies,orsociologymajors.Howdoweknowwhichsubjectsbenefitsociety?Easy.Averagestartingsalariesgiveaclearindicationofwhattypeoftrainingsocietyneedsitsnewworkerstohave.Certainly,there'rebenefitstoacollegemajorthejobastudentcanperform.Butifwe'retalkingaboutthebenefitstosociety,theonlythingthatmattersiswhatthemajorenablesthestudenttoproduceforsociety.Andthevalueofwhatthestudentcanprod