防冻剂28d收缩率比试验记录表

2019年12月四级真题(全三套)-2019年12月四级真题(全三套)-PAGE2019年12月四级真题(全三套)-2015年12月大学英语四级考试真题(第一套)PartⅠWriting(30minutes)Directions：Forthispart，youareallowed30minutestowritealettertoaforeignfriendwhowantstoteachEnglishinChina。Pleaserecommendacitytohim。Youshouldwriteatleast120wordsbutnomorethan180words。PartⅡListeningComprehension(30minutes)SectionADirections:Inthissection,youwillhear8shortconversationsand2longconversations.Attheendofeachconversation,oneormorequestionswillbeaskedaboutwhatwassaid.Boththeconversationandthequestionswillbespokenonlyonce.Aftereachquestiontherewillbeapause.Duringthepause,youmustreadthefourchoicesmarkedA,B,C,andD.anddecidewhichisthebestanswer.ThenmarkthecorrespondingletteronAnswer.SheetIwithasinglelinethroughthecenter.Questions l and 2 are based on the news report you have just heard.   Many facilities were destroyed by a wandering cow. B) A wandering cow knocked down one of its fences. C) Some tourists were injured by a wandering cow. D) A wandering cow was captured by the police.   It was shot to death by a police officer. B) It found its way back to the parkC) It became a great attraction for tourists. D) It was sent to the animal control department. Questions 3 and 4 are based on the news report you have just heard.   It is the largest of its kind. B) It is going to be expanded. C) It is displaying more fossil specimens. D) It is staring an online exhibition.   A collection of bird fossils from Australia.  B) Photographs of certain rare fossil exhibits. C) Some ancient wall paintings from Australia. D)Picturesbywinnersofawildlifephoto.Questions 5 to 7 are based on the news report you have just heard.   Pick up trash. B) Amuse visitors. C) Deliver messages.  D) Play with children.   They are especially intelligent. B) They are childrenC) They are quite easy to tame. D) They are clean and pretty.   Children may be harmed by the rooks. B) Children may be tempted to drop litter. C) Children may contract bird diseases.  D) Children may overfeed the rooks. SectionBDirections...Inthissection,youwillhear3shortpassages.Attheendofeachpassage,youwillhearsomequestions.Boththepassageandthequestionswillbespokenonlyonce.Afteryouhearaquestion,youmustchoosethebestanswerfromthefourchoicesmarkedA,B,C.andD.ThenmarkthecorrespondingletteronAnswerSheet1withasinglelinethroughthecenter.Questions 8 to 11 are based on the conversation you have just heard.   It will be produced at Harvard University.  B) It will be hosted by famous professors. C) It will cover different areas of science. D) It will focus on recent scientific discoveries.   It will be more futuristic. B) It will be more systematic. C) It will be more entertaining. D) It will be easier to understand.   People interested in science.B) Youngsters eager to explore. C) Children in their early teens.    Offer professional advice.  B) Provide financial support. C) Help promote it on the Internet. D) Make episodes for its first season. Questions 12 to 15 are based on the conversation you have just heard.   Unsure. B) Helpless. C) Concerned. D) Dissatisfied.   He is too concerned with being perfect.  B) He loses heart when faced with setbacks. C) He is too ambitious in achieving goals. D) He takes on projects beyond his ability.   Embarrassed. B) Unconcerned. C) Miserable. D) Resentful.   Try to be optimistic whatever happens. B) Compare his present with his past only. C) Always learn from othersD) Treat others the way he would be treated. SectionCDirections:Inthissection,youwillhearapassagethreethepassageisreadforthefirsttime,youshouldlistencarefullyforitsgeneralidea.Whenthepassageisreadforthesecondtime,youarerequiredtofillintheblankswiththeexactwordsyouhavejustheard.Finally,whenthepassageisreadforthethirdtime,youshouldcheckwhatyouhavewritten.Questions 16 to 18 are based on the passage you have just heard.   They have a stronger sense of social responsibility. B) They are more likely to succeed in the humanities. C) They are more likely to become engineers. D) They have greater potential to be leaders.   Praise girls who like to speak up frequently. B) Encourage girls to solve problems on their own. C) Insist that boys and girls work together more. D) Respond more positively to boys comments.   Offer personalized teaching materials. B) Provide a variety of optional courses. C) Place great emphasis on test scores. D) Pay extra attention to top students. Questions 19 to 21 are based on the passage you have just heard.   It often rains cats and dogs. B) It seldom rains in summer time. C) It does not rain as much as people think. D) It is one of the most rainy cities in the US.   They drive most of the time. B) The rain is usually very light. C) They have got used to the rain. D) The rain comes mostly at night.   It has a lot of places for entertainment. B) It has never seen thunder and lighting. C) It has fewer cloudy days than any other coastal city. D) It has mild weather both in summer and in winter. Questions 22 to 25 are based on the passage you have just heard.   It occurs when people are doing a repetitive activity. B) It results from exerting oneC) It happens when people engage in an uncommon activity. D) It comes from staining one  Blood flow and body heat increase in the affected area. B) Body movements in the affected area become difficult. C) They begin to make repairs immediately. D) They gradually become fragmented.   About one week. B) About two days. C) About ten days. D) About four weeks.   Apply muscle creams. B) Drink plenty of water. C) Have a hot shower. D) Take pain-killers.. PartⅢReadingComprehension(40minutes)SectionADirections:Inthissection,thereisapassagewithtenarerequiredtoselectonewordforeachblankfromalistofchoicesgiveninawordbankfollowingthethepassagethroughcarefullybeforemakingyourchoiceinthebankisidentifiedbyamarkthecorrespondingletterforeachitemonAnswerSheet2withasinglelinethroughthemaynotuseanyofthewordsinthebankmorethanonce.Questions26to35arebasedonthefollowingpassage.Whentravellingoverseas,doyoubuywaterinplasticbottlesortakeyourchanceswithtapwater?lmagineyouarewanderingaboutonaThaiislandor_26_theruinsof’shotsoyougrababottleofwaterfromalocalvendorItisthesafe,sanethingtodo,rightThebottle_27_,andthelabelsays“purewater”,butmaybewhatinsideisnotso_28_.Wouldyoustillbedrinkingitifyouknewthatmorethan90percentofallbottledwatersoldaroundthewor_29_microplastics?That'stheconclusionofarecently_30_study,whichanalyzed259bottlesfrom11brandssoldinninecountries,_31_anaverageof325plasticparticlesperliterofwater.Thesemicroplasticsincludeda_32_commonlyknownasPETandarewidelyusedinthemanufactureofclothingandfoodand_33_containers.ThestudywasconductedattheStateUniversityofNewYorkonbehalfofOrbMedia,ajournalismorganization.Aboutamillionbottlesareboughteveryminute,notonlybythirstytouristsbutalsobymanyofthebillionworldwidewholivewithunsafedrinkingwater.Confrontedwiththis_34_severalbottled-watermanufacturersincludingNestleandCoco-Colaundertooktheirownstudiesusingthesamemethodology.Thesestudiesshowedthattheirwaterdidcontainmicroplastics,butfarlessthantheOrbstudysuggested.Regardless,theWorldHealthOrganizationhasnowlaunchedareviewintothe__35_healthrisksofdrinkingwaterfromplasticbottles.A) adequate B) admiring C) contains D) defending E) evidence F) instant G) liquid H) modified I) natural J) potential K) released L) revealing M) sealed N) solves O) substance SectionBDirections:Inthissection,youaregoingtoreadapassagewithtenstatementsattachedtoeachstatementcontainsinformationgiveninoneoftheparagraphs.ldentifytheparagraphfromwhichtheinformationisderived.Youmaychooseaparagraphmorethanonce.Eachparagraphismarkedwithaletter.AnswerthequestionsbymarkingthecorrespondingletteronAnswerSheet2.TheQuietHeroismofMailDelivery[A]OnWednesday,apolarwindbroughtbittercoldtotheMidwest.Overnight,Chicagoreachedalowof21degreesFahrenheitbelowzero,makingitslightlycolderthanAntarctica,Alaska,andtheNorthPole.Windchillswere64degreesbelowzeroinParkRapids,Minnesota,and45degreesbelowzeroinBuffalo,NorthDakota,accordingtotheNalionialWeatherService.Schools,restaurants,andbusinessesclosed,.andmorethanflightshavebeencanceled.[B]EventheUnitedStatesPostalService(USPS)suspendedmaildeliverytemporarilyDuetothisarcticoutbreakandconcernsforthesafetyofUSPSemployees,USPSannouncedWednesdaymorningthePostalServiceissuspendingdeliveryJan30inthefollowing3-digit71PCodelocationsTwelve regionswerelistedasunsafeonWednesday;onThursday,eightremained.[C]Asglobalsurfacetemperaturesincrease,S0doesthelikelihoodofextremeweather.In2018alone,wildfires,volcaniceruptions.hurricanes,mudslides,andothernaturaldisasterscostatleast$49billionintheUnitedStates.AsmycolleagueVannNewkirkreported,PuertoRicoisstillconfrontingeconomicandstructuraldestructionandresourcescarcityfrom2057HurricaneMaria.Naturaldisasterscanwreckacommunity'sinfrastructure,disruptingsystemsformonthsoryears.Someservices;however,remindusthatlifewilleventuallyreturn,insomeform,tonormal.[D]Daysafterthedeadly2017wildfiresinSantaRosa,California,adronecaughtfootageofaUSPSworker,TrevorSmith,drivingthroughburnedhomesinthatfamiliarwhilevan,collectingmailinanaffectedarea:Thevideoisstriking:Theoperationisfamiliar,butthe'scenelooksliketheendoftheworldAccordingtoRaeAnnHaight,theprogrammanagerforthenational-preparednessofficeatUSPS,SmithwasfulfillingarequestmadebysomeofthehomeownerstopickupanymailthatwasletuntouchedForSmiththiswasjustanotherdayonthejobI followedmyroutelikeInormallydo,Smithtoldareporter.“Asl'dcomeacrossaboxthatwasupbutwithnohouse,Ichecked,andtherewasmail--outgoingmail-init.Andsowepickedthoseupand carried on..[E]USPShassophisticatedemergencyplansfornaturaldisasters.Acrossthecountry;285emergency-managementteamsaredevotedtocrisiscontrol.TheseteamsaretrainedannuallyusingaframeworkknownasthethreePs:people,property,product.Aftermailservicestopsduetoweather,theagency'stoppriorityisensuringthatemployeesaresafe.Thenitevaluatesthehealthofinfrastructure,suchastheroadsthatmailcarriersdriveon.Finally,itdecideswhenandhowtore-openoperations.thedestructionisextreme,mailaddressedtothearea'willgetsentelsewhere.InresponsetoHurricaneKatrinain2005,USPSredirectedincomingNewOrleansmailloexistingmailfacilitiesinHouston.MailthatwasalreadyprocessedinNewOrleansfacilitieswasmovedtoanupperfloorsoitwouldbeprotectedfromwaterdamage.[F]Assoonasit'ssafeenoughtobeoutside,couriersstartdistributingaccumulatedmailonthestill-accessibleroutes.USPSurgesthosewithoutstandingaddressestofilechange-of-addressforms.withtheirnewlocation.AfterHurricaneKatrinahitin2005,mailfacilitiesweresetupindozensofotherlocationsacrossthecountryinthetwoweeksthatUSPSwasunabletoprovidestreetdelivery.[G]Everyday,USPSprocesses,onaverage,millionpiecesofmailanythingfrompostcardstoSocialSecuritycheckstomedicine.SpokespeoplefrombothUSPSandUPStoldmeallmailisimportant.Butsomemailcanbeextremelysensitiveandtimely.AccordingtodatareleasedinJanuary2017,56percentofbillsarepaidonline,whichmeansthatjustunderhalfofpaymentsstillrelyondeliveryservicestobecompleted.[H]ltcanbehardtoidentifywhichparcelsarecarryingcrucialitemssuchasSocialSecuritychecks,butUSPSandUPStrytheirbesttoprioritizesensitivematerial.TheywillcoordinatewiththeSocialSecurityAdministrationtomakesurethatSocialSecuritychecksreachtherightpeopleinatimelyfashion.AfterHurricaneFlorenceandHurricaneMichaellastfall,USPSworkedwithstateandlocalelectionboardstomakesurethatabsenteeballotswereavailableandreceivedontime.[I]Mailcompaniesarelogisticscompanies,whichputstheminaspecialpositiontohelpwhendisasterstrikes.Ina2011USPScasestudy,theagencyemphasizeditsmassiveinfrastructureuniquefederalasset"tobecalleduponinadisasterorterroristattack.IthinkwereuniqueasafederalagencyUSPSofficialMikeSwigarttoldme,becausewe'reinliterallyeverycommunityinthiscountry....We'reobligatedtodelivertothatpointonadailybasis.[J]Privatecouriercompanies,whichhavemoredollarstospend,usetheirexpertiseinlogisticstohelprevitalizedamagedareasafteradisaster..Formorethanadecade,FedExhassupportedtheAmericanRedCrossinitsefforttogetemergencysuppliestoareasaffectedbydisasters,bothdomesticallyandinternationally.In2012,thecompanydistributedmorethan1,200MedPackstoMedicalReserveCorpsgroupsinCalifornia,anddonatedspaceformillionpoundsofcharitableshippingglobally.LastOctober,thecompanypledged$1millionincashandtransportationsupportforHurricanesFlorenceandMichael.UPS'scharitablearm,theUPSFoundation,usesthecompany'slogisticstohelpdisaster-struckareasrebuildWerealizethatasacompanywithpeople,trucks,warehouses,weneededtoplayalargerrole,"saidEduardoMartinez,thepresidentoftheUPSFoundation.Thecompanyemploysitstrucksandplanestodeliverfood,medicine,andwater.ThedaybeforeIspoketoMartinezNovember,hehadbeentouringthedamagefromHurricaneMichaelinFloridawiththeAmericanRedCross.'Wehaveanobligationtomakesureourcommunitiesarethriving,prosperous,said.[K]Rebuildingcantakealongtime,andeventhen,impressionsofthedisastermaystillremain.Returningtoasenseofnormalcycanbedifficult,butsomesmallroutingdeliverybeingoneofthem--mayhelpresidentsrememberthattheircommunitiesarestilltheircommunitiesthentheyseethatcarrierbackoutonthestreetSwigartsaid,that'sthefirstsigntothemthatlifeisstartingtoreturntonormal::36.The United States Postal Service has a system to ensure its employees safety.37.OneofficialsaysUSPSisuniqueinthatithasmoredirectreachtocommunitiescomparedwiththefederalagencies38.Naturaldisasterscanhavealong-lastingimpactoncommunitylife.39.Maildeliveryservicei$stillresponsibleforthecompletionofalmosthalfof.Thesightofamailmanonthestreetisareassuringsignoflifebecomingnormalagain.40. Thesightofamailmanonthestreetisareassuringsignoflifebecomingnormalagain.41.AfterHurricaneKatrinainterruptedroutinedelivery,temporarymailservicepointsweresetup.42.Postalserviceinsomeregionsinthe.wassuspendedduetoextremecoldweather.43.Privatepostalcompaniesalsosupportdisasterreliefeffortsbydistributingurgentsupplies.44.AdedicatedUSPSemployeewasonthejobcarryingoutdutiesinspiteofextremeconditions.45.Postalservicesworkhardtoidentifyitemsthatrequireprioritytreatment.sectioncQuestions46to50arebasedonthefollowingpassage.ProfessorAshokGoelofGeorgiaTechdevelopedanartificiallyintelligentteachingassistanttohelphandletheenormousnumberofstudentquestionsintheonlineclass,KnowledgeBasedArtificialIntelligence.ThisonlinecourseisacorerequirementofGeorgiaTech'sonlineMasterofScienceinComputerScienceprogram..ProfessorGoelalreadyhad8teachingassistants,butthat enough to dealwiththeoverwhelmingnumberofquestionsfromstudents.Manystudentsdropoutofonlinecoursesbecauseofthelackofteachingsupport.Whenstudentsfeelisolatedorconfusedandreachoutwithquestionsthatgounanswered,theirmotivationtocontinuebeginstofade.ProfessorGoeldecidedtodosomethingtoremedythissituationandhissolutionwastocreateavirtualassistantnamedJillWatson,whichisbasedontheIBMWatsonplatform.GoelandhisteamdevelopedseveralversionsofJillWatsonbeforereleasinghertotheonlineforumsAtfirst,thevirtualassistantwasn’ttoogreat.ButGoelandhisteamsourcedtheonlinediscussionforumtofindall40,000questionsthathadeverbeenaskedsincetheclasswaslaunched.ThentheybegantofeedJillthequestionsandanswers.Aftersomeadjustmentandsufficienttime,Jillwasabletoanswerthestudents'questionscorrectly97%ofthetime.Thevirtualassistantbecamesoadvancedandrealisticthatthestudentsdidn’tknowshewasacomputer.Thestudents,whowerestudyingartificialintelligence,wereinteractingwithartificialintelligenceandcouldn’ttellitapartfromarealhumanbeing.Goel'didn’tinformthemaboutJill’strueidentityuntilApril26.Thestudentswereactuallyverypositiveabouttheexperience.ThegoalofProfessorGoelsvirtualassistantnextyearistotakeoveranswering40%ofallquestionsposedbystudentsontheonlineforum.Thename,JillWatson,willofcourse,changetosomethingelsenextsemester.ProfessorGoelhasamuchrosieroutlookonthefutureofAlthansay,ElonMusk,StephenHawking,BillCatesorSteveWozniak.46.WhatdowelearnaboutKnowledge-BasedArtificialIntelligence?A)ltisarobotthatcananswerstudentquestions.B)ltisacoursedesignedforstudentstolearnonline.C)ltisahigh-techdevicethatrevolutionizesteaching.D)ltisacomputerprogramthataidsstudentlearning.47.WhatproblemdidProfessorGoelmeetwith?A)Hisstudentswereunsatisfiedwiththeassistarts.B)Hiscoursewastoodifficultforthestudents.C)Studentsquestionsweretoomanytohandle.D)Toomanystudentsdroppedoutofhiscourse.48.WhatdowelearnaboutJillWatson?A)Sheturnedouttobeagreatsuccess.B)Shegotalongprettywellwithstudents.C)Shewasunwelcometostudentsatfirst.D)Shewasreleasedonlineasanexperiment.        ? A) They thought she was a bit too artificial.  B) They found her not as capable as expected. C) They could not but admire her knowledge. D) They could not tell her from a real person. 50 What does Professor Goel plan to do next with Jill Watson? A) Launch different versions of her online. B) Feed her with new questions and answers. C) Assign her to answer more of studentsD) Encourage students to interact with her more freely. PassageTwoQuestions51to55arebasedonthefollowingpassage.Thinkingsmall,beingengaging,andhavingasenseofhumordon'thurt.Thoseareafewofthetraitsofsuccessfulsciencecrowdfundingeffortsthatemergefromarecentstudythatexaminednearly400campaigns.Buthavingalargenetworkandsomepromotionalskillsmaybemorecrucial.Crowdfunding,raisingmoneyforaprojectthroughonlineappeals,hastakenoffinrecentyearsforeverythingfrommakingmoviestobuildingwater-savinggadgets.ScientistshavetriedtotapInternetdonors,too,withmixedsuccess.Someraisedmorethantwicetheirgoal,butothershavefallenshorto1reachingmoremodesttargets.Todeterminewhatseparatessciencecrowdfundingtriumphsfromfailures,ateamledbysciencecommunicationsscholarMikeSchferoftheUniversityofZurichinSwitzerlandexaminedthecontentoftheWebPagesfor371recentcampaigns.Fourtraitsstoodoutforthosethatachievedtheirgoals,theresearchersreportinPublicUnderstandingofScienceForone,theyuseacrowdfundingplatformthatspecializesinraisingmoneyforscience,andnotjustanykindofproject.AlthoughsiteslikeKickstartertakeallcomers,platformssuchasExperiment.Medstartr.,andonlypresentscientificprojects.Foranothertheypresenttheprojectwithafunnyvideobecausegoodvisualsandasenseofhumorimprovedsuccess.Mostofthemengagewithpotentialdonorssinceprojects.thatansweredquestionsfrominteresteddonorsandpostedlabnotesfaredbetter.Andtheytargetasmallamountofmoney.Theprojectsincludedinthestudyraised$4000onaverage,with309ofprojectsreceivinglessthan$1000.Themoremoneyaprojectsought,thelowerthechanceitreacheditsgoal,theresearchersFound.Otherfactorsmayalsosignificantlyinfluenceaproject'ssuccess,mostnotably,thesizeofascientist'spersonalandprofessionalnetworks,andhowmucharesearcherpromotesaprojectonhisotherown.Thosetwofactorsarebyfarmorecriticalthanthecontentonthepage.Crowdfundingcanbepartofresearcherseffortstoreachthepublic,andpeoplegivebecausetheyfeelaconnectiontotheperson"whoisdoingthefundraisingnotnecessarilytothescience.51.Whatdowelearnaboutthescientiststryingtoraisemoneyonlinefortheirprojects?A)Theydidnotraisemuchduetomodesttargets.B)Theymadeuseofmixedfundraisingstrategies.C)Notallofthemachievedtheiranticipatedgoals.D)Mostofthemputmoviesonlineforthepurpose.52.WhatisthepurposeofMikeScheresearchofrecentcrowdfundingcampaigns?A)Tocreateattractivecontentforsciencewebsites.B)Toidentifyreasonsfortheirdifferentoutcomes.C)Tohelpscientiststolaunchinnovativeprojects.D)Toseparatescienceprojectsfromgeneralones.53.Whattraitcontributestothesuccessofacrowdfundingcampaign?A)ThepotentialbenefittofuturegenerationsB)lt’sinteractionwithprospectivedonors.C)lt’soriginalityinaddressingfinancialissuesD)Thevalueoftheproposedproject.54.Whatdidtheresearchersthinkofthefinancialtargetsofcrowdfundingprojects?A)Theyshouldbesmalltobesuccessful.B)Theyshouldbebasedonactualneeds.C)Theyshouldbeassessedwithgreatcare.D)Theyshouldbeambitioustogainnotice.55.Whatmotivatespeopletodonateinacrowdfundingcampaign?A)Theeaseofaccesstothecontentofthewebpage.B)Theirdesiretocontributetothecauseofscience.C)Thesignificanceandinfluenceoftheprojectitself.D)Theirfeelingofconnectiontothescientiststhemselves.PartIVTranslation(30minutes)Directions:Forthispart,youareallowed30minutestotranslateapassagefromChineseintoEnglish.Youshouldwriteyouranswer.onAnswer.Sheet2.中国家庭十分重视孩