2025年四级考试题真题及答案

2025年四级考试题真题及答案本文借鉴了近年相关经典试题创作而成，力求帮助考生深入理解测试题型，掌握答题技巧，提升应试能力。听力部分SectionADirections:Inthissection,youwillhear8shortconversations.Attheendofeachconversation,aquestionwillbeaskedaboutwhatwassaid.Boththeconversationandthequestionwillbespokenonlyonce.Aftereachquestiontherewillbeapause.Duringthepause,youmustreadthefoursuggestedanswersmarkedA),B),C)andD),anddecidewhichoneisthebestanswer.Example:Youwillhear:Youwillread:A)2hours.B)3hours.C)4hours.D)5hours.Fromtheconversationweknowthatthewomanwillbeawayfortwohours.Therefore,A)"2hours"isthecorrectanswer.Questions:1.Conversation:M:Hi,haveyouseenthenewmovie"TheTimeTraveler'sDilemma"?W:Yes,Iwenttoseeitlastnight.Itwasquiteinteresting.Q:Whatdoesthewomanthinkofthemovie?A)It'sboring.B)It'sinteresting.C)It'stoolong.D)It'snotworthwatching.2.Conversation:M:I'mreallystrugglingwithmystatisticshomework.W:Don'tworry,Icanhelpyouwiththat.I'mgoodatstatistics.Q:Whatwillthewomanprobablydonext?A)Shewillgivethemanherhomework.B)Shewillhelpthemanwithhishomework.C)Shewillborrowtheman'shomework.D)Shewilldothehomeworktogetherwiththeman.3.Conversation:M:Haveyouheardaboutthenewcampuscafé?W:Yes,Iwentthereforlunchtoday.Thefoodisgreat,butit'sabitexpensive.Q:Whatdoesthewomanthinkofthecafé?A)Thefoodisnotgood.B)Thefoodisgoodbutexpensive.C)It'stoocrowded.D)It'snotworthvisiting.4.Conversation:M:I'mthinkingaboutjoiningthedebateclub.W:That'sagreatidea!You'reagoodspeaker.Q:Whatdoesthewomanthinkoftheman?A)Heisnotagoodspeaker.B)Heisnotinterestedinthedebateclub.C)Heisagoodspeaker.D)Heisnotgoodatpublicspeaking.5.Conversation:M:I'mreallyexcitedabouttheupcomingtriptoJapan.W:Thatsoundsfantastic!Areyougoingtovisitanyspecificplaces?Q:Whataretheymainlytalkingabout?A)Theirjobs.B)Theirstudies.C)TheirtriptoJapan.D)Theirfavoritehobbies.6.Conversation:M:Ican'tbelievehowlateitis.Iforgottosetmyalarm.W:Don'tworry,youcantakeataxi.It'snotfarfromhere.Q:Whatwillthemanprobablydonext?A)Hewillgotobed.B)Hewilltakeataxi.C)Hewillsethisalarm.D)Hewillwalkhome.7.Conversation:M:I'mreallytiredofthisweather.It'sbeenrainingfordays.W:Iknow,right?Ican'twaitforthesuntocomeout.Q:Whataretheytalkingabout?A)Theirnewshoes.B)Theweather.C)Theirplansfortheweekend.D)TheirfavoriteTVshows.8.Conversation:M:Haveyoufinishedreadingthebook"ToKillaMockingbird"?W:Yes,Ifinishedityesterday.Itwasaverytouchingstory.Q:Whatdoesthewomanthinkofthebook?A)It'sboring.B)It'sinteresting.C)It'stoodifficult.D)It'snotworthreading.SectionBDirections:Inthissection,youwillhear2shortpassages.Attheendofeachpassage,therewillbe3questions.Boththepassageandthequestionswillbespokenonlyonce.Aftereachquestiontherewillbeapause.Duringthepause,youmustreadthefoursuggestedanswersmarkedA),B),C)andD),anddecidewhichoneisthebestanswer.Passage1:Thelocallibraryhasbeenacornerstoneofcommunitylifeformanyyears.Itprovidesawiderangeofresourcesforpeopleofallages,fromchildrentotheelderly.Recently,thelibraryhasbeenfacingasignificantchallenge:decliningattendanceandfundingcuts.Despitethesedifficulties,thelibrariansandstaffareworkingtirelesslytokeepthelibraryrelevantandaccessible.Theyhaveintroducednewprograms,suchasdigitalliteracyworkshopsandonlinebookclubs,toattractmorepatrons.Thecommunityisalsocomingtogethertosupportthelibrary,withlocalbusinessesdonatingbooksandorganizingfundraisingevents.Thefutureofthelibraryseemsbrighterwiththeseefforts,anditcontinuestobeavitalpartofthecommunity.Questions:1.Whatisthemainproblemthelocallibraryisfacing?A)Itisrunningoutofbooks.B)Itisfacingdecliningattendanceandfundingcuts.C)Itistoosmall.D)Itisnotaccessibletopeople.2.Whatnewprogramshasthelibraryintroduced?A)Movienightsandbookfairs.B)Digitalliteracyworkshopsandonlinebookclubs.C)Readingcontestsandauthorvisits.D)Summerreadingprogramsandhomeworkhelp.3.Howisthecommunitysupportingthelibrary?A)Bydonatingbooksandorganizingfundraisingevents.B)Byattendingmoreevents.C)Bysettingupanewbranch.D)Byhiringmorelibrarians.Passage2:Theannualsciencefairisamuch-anticipatedeventatourschool.Itbringstogetherstudentsfromallgradestoshowcasetheirinnovativeprojectsandscientificknowledge.Thisyear'sfairwasparticularlyexciting,withavarietyofprojectsthatrangedfromenvironmentalsciencetorobotics.Thejudges,whowerecomposedoflocalscientistsandeducators,wereimpressedbythecreativityandeffortputintoeachproject.Onestandoutprojectwasasolar-poweredcardesignedbyagroupofstudentswhoaimedtopromotesustainabletransportation.Anothernotableprojectwasamachinethatcouldconvertwasteintousableenergy.Thefairnotonlyfosteredaloveforscienceamongstudentsbutalsohighlightedtheimportanceofinnovationandenvironmentalawareness.Questions:1.Whatisthemainpurposeoftheannualsciencefair?A)Toraisemoneyfortheschool.B)Toshowcasestudents'innovativeprojectsandscientificknowledge.C)Tohostavarietyofsportsevents.D)Topromoteextracurricularactivities.2.Whowerethejudgesatthesciencefair?A)Teachersandstudents.B)Localscientistsandeducators.C)Parentsandcommunitymembers.D)Professionalathletes.3.Whichprojectwashighlightedasastandout?A)Asolar-poweredcar.B)Amachinethatconvertswasteintousableenergy.C)Aprojectonancientcivilizations.D)Astudyonanimalbehavior.ReadingPartSectionADirections:Inthissection,thereare4readingpassages.Eachpassageisfollowedbysomequestionsorunfinishedstatements.ForeachofthemtherearefourchoicesmarkedA),B),C)andD).YoushoulddecideonthebestchoiceandmarkthecorrespondingletteronAnswerSheet2withasinglelinethroughthecentre.Passage1:Theriseofsocialmediahasfundamentallychangedthewaywecommunicateandshareinformation.PlatformslikeFacebook,Twitter,andInstagramhavebecomeintegraltoourdailylives,allowingustoconnectwithfriends,family,andevenstrangersfromaroundtheworld.Whilesocialmediahasnumerousbenefits,italsocomeswithitsfairshareofchallengesanddrawbacks.Oneofthemostsignificantbenefitsofsocialmediaisitsabilitytobridgegeographicalbarriers.Throughtheseplatforms,wecanstayintouchwithlovedoneswholivefaraway,shareupdates,andevenparticipateinreal-timeevents.Thishasmadetheworldfeelsmallerandmoreconnected.Additionally,socialmediaprovidesaplatformforexpressionandcreativity.Userscansharetheirthoughts,opinions,andcreativeworkswithaglobalaudience,fosteringasenseofcommunityandcollaboration.However,theriseofsocialmediahasalsoledtoseveralnegativeconsequences.Oneofthemostpressingissuesisthespreadofmisinformation.Falseinformationandconspiracytheoriescanspreadrapidlyonsocialmedia,oftenamplifiedbyalgorithmsthatprioritizeengagementoveraccuracy.Thiscanleadtopublicconfusionandevensocialunrest.Anothersignificantconcernistheimpactonmentalhealth.Theconstantcomparisontoothers'curatedlivesonsocialmediacanleadtofeelingsofinadequacy,anxiety,anddepression.Moreover,theaddictivenatureoftheseplatformscanleadtoexcessivescreentime,negativelyaffectingsleeppatternsandoverallwell-being.Despitethesechallenges,socialmediacontinuestoevolveandadapt.Manyplatformsareimplementingmeasurestocombatmisinformation,suchasfact-checkinglabelsandalgorithmadjustments.Thereisalsoagrowingawarenessoftheneedfordigitalliteracyandmindfulsocialmediause.Aswecontinuetonavigatethedigitallandscape,itiscrucialtoharnessthebenefitsofsocialmediawhilemitigatingitsnegativeimpacts.Questions:1.Whatisthemaintopicofthepassage?A)Thebenefitsofsocialmedia.B)Thechallengesofsocialmedia.C)Theriseofsocialmedia.D)Theevolutionofsocialmedia.2.Accordingtothepassage,whatisoneofthebenefitsofsocialmedia?A)Ithelpsinspreadingmisinformation.B)Itbridgesgeographicalbarriers.C)Itpromotesmentalhealthissues.D)Itencouragesexcessivescreentime.3.Whatisoneofthenegativeconsequencesofsocialmediamentionedinthepassage?A)Itfostersasenseofcommunity.B)Itprovidesaplatformforexpression.C)Itspreadsmisinformation.D)Itenhancesmentalwell-being.4.Whatmeasuresarebeingtakentocombatmisinformationonsocialmedia?A)Increasingscreentime.B)Implementingfact-checkinglabelsandalgorithmadjustments.C)Encouragingmoreusers.D)Reducingthenumberofsocialmediaplatforms.Passage2:Climatechangeisoneofthemostsignificantchallengesfacingourplanettoday.Theincreasingconcentrationofgreenhousegasesintheatmosphere,primarilyduetohumanactivities,hasledtoariseinglobaltemperatures,resultinginarangeofenvironmentalandsocio-economicimpacts.Theconsequencesofclimatechangearefar-reachingandaffecteverycorneroftheglobe,frompolaricecapstotropicalforests.Oneofthemostvisibleeffectsofclimatechangeisthemeltingofpolaricecapsandglaciers.Thisnotonlycontributestorisingsealevelsbutalsodisruptsthenaturalhabitatsofnumerousspecies,suchaspolarbearsandpenguins.Thelossofthesehabitatscanhavecascadingeffectsontheentireecosystem.Additionally,theriseinsealevelsposesasignificantthreattocoastalcommunities,increasingtheriskoffloodinganderosion.Anothermajorimpactofclimatechangeistheincreasedfrequencyandintensityofextremeweatherevents.Heatwaves,droughts,hurricanes,andwildfiresarebecomingmorecommon,causingwidespreaddamagetoinfrastructure,agriculture,andnaturalhabitats.Theseeventsnotonlyresultinlossoflifeandpropertybutalsohavesignificanteconomicimplications,affectingindustriessuchasagriculture,tourism,andinsurance.Addressingclimatechangerequiresamultifacetedapproach.Reducinggreenhousegasemissionsiscrucial,andthiscanbeachievedthroughthetransitiontorenewableenergysources,improvingenergyefficiency,andadoptingsustainablepracticesinindustriesandagriculture.Additionally,investinginclimateresilienceandadaptationmeasuresisessentialtoprotectcommunitiesandecosystemsfromtheinevitableimpactsofclimatechange.Internationalcooperationandpolicyagreements,suchastheParisAgreement,playavitalroleincoordinatingglobaleffortstocombatclimatechange.Questions:1.Whatisthemaintopicofthepassage?A)Theeffectsofclimatechange.B)Thecausesofclimatechange.C)Thesolutionstoclimatechange.D)Theeconomicimpactofclimatechange.2.Accordingtothepassage,whatisoneofthevisibleeffectsofclimatechange?A)Theincreaseinrenewableenergyusage.B)Themeltingofpolaricecapsandglaciers.C)Thereductioningreenhousegasemissions.D)Thegrowthofcoastalcommunities.3.Whatisanothermajorimpactofclimatechangementionedinthepassage?A)Thedecreaseinextremeweatherevents.B)Theincreaseinagriculturalproductivity.C)Theimprovedinfrastructure.D)Theincreasedfrequencyandintensityofextremeweatherevents.4.Whatmeasuresarementionedtoaddressclimatechange?A)Increasinggreenhousegasemissions.B)Transitioningtorenewableenergysources.C)Reducinginternationalcooperation.D)Ignoringclimateresilienceefforts.Passage3:Thedigitalrevolutionhastransformedthewaywework,learn,andinteractwiththeworld.Oneofthemostsignificantdevelopmentsinthisrevolutionistheriseofremotework.Theabilitytoworkfromhomeoranylocationhasbecomeincreasinglyfeasibleduetoadvancementsintechnology,suchashigh-speedinternet,videoconferencingtools,andcollaborativesoftware.Thisshifthasnotonlyprovidedemployeeswithgreaterflexibilitybuthasalsoopenedupopportunitiesforbusinessestoaccessaglobaltalentpool.Thebenefitsofremoteworkarenumerous.Employeescansavetimeandmoneyoncommuting,reducestressrelatedtoofficeenvironments,andhaveabetterwork-lifebalance.Forbusinesses,remoteworkcanleadtoloweroverheadcosts,increasedproductivity,andreducedturnoverrates.Additionally,companiescanattractandretaintoptalentbyofferingremoteworkoptions,whichisparticularlybeneficialincompetitiveindustries.However,remoteworkalsocomeswithitschallenges.Maintainingteamcohesionandcommunicationcanbemoredifficultwhenteammembersarenotphysicallypresent.Managersneedtodevelopnewstrategiestoensurethatremoteteamsremainproductiveandengaged.Additionally,theblurringofboundariesbetweenworkandpersonallifecanleadtoburnoutanddecreasedwell-beingifnotmanagedproperly.Employeesmayfinditchallengingtodisconnectfromwork,leadingtolongerworkinghoursandincreasedstress.Despitethesechallenges,thetrendtowardsremoteworkislikelytocontinueandevolve.Astechnologycontinuestoadvance,newtoolsandplatformswillemergetofacilitateremotecollaborationandcommunication.Companieswillneedtoadapttheirmanagementpracticesandcreateasupportiveremoteworkculturetomaximizethebenefitsofthisworkmodel.Thedigitalrevolutionhasirrevocablychangedthelandscapeofwork,andremoteworkisattheforefrontofthistransformation.Questions:1.Whatisthemaintopicofthepassage?A)Thebenefitsofremotework.B)Thechallengesofremotework.C)Theriseofremotework.D)Theimpactofremoteworkonbusinesses.2.Accordingtothepassage,whatisoneofthebenefitsofremotework?A)Itincreasescommutingtime.B)Itprovidesemployeeswithgreaterflexibility.C)Itraisesoverheadcosts.D)Itdecreasesproductivity.3.Whatisoneofthechallengesofremoteworkmentionedinthepassage?A)Itimprovesteamcohesion.B)Itmaintainsclearwork-lifeboundaries.C)Itcanbemoredifficulttomaintainteamcohesion.D)Itreducesstressforemployees.4.Whatisthefuturetrendofremoteworkmentionedinthepassage?A)Itwilldeclineduetotechnologicaladvancements.B)Itwillcontinueandevolvewithtechnologicaladvancements.C)Itwillremainstaticdespitetechnologicaladvancements.D)Itwillbereplacedbytraditionalofficework.Passage4:Theimportanceofeducationcannotbeoverstated.Itisthefoundationforindividualdevelopment,societalprogress,andglobalcompetitiveness.Educationequipsindividualswiththeknowledge,skills,andcriticalthinkingabilitiesnecessarytonavigateanincreasinglycomplexworld.Fromearlychildhoodeducationtohighereducation,theeducationaljourneyplaysapivotalroleinshapingindividualsandcommunities.Earlychildhoodeducationlaysthegroundworkforfuturelearning.Itfocusesonplay-basedlearning,socialdevelopment,andthedevelopmentoffoundationalskillssuchasliteracyandnumeracy.Researchhasshownthatqualityearlychildhoodeducationcanhavelong-lastingpositiveeffectsonachild'scognitiveandsocialdevelopment,settingthestageforsuccessinlateryears.Primaryandsecondaryeducationcontinuetobuilduponthefoundationslaidinearlychildhood.Thesestagesfocusonabroadercurriculum,includingsubjectssuchasmathematics,science,languagearts,andsocialstudies.Educationattheselevelsnotonlyimpartsknowledgebutalsofosterscriticalthinking,problem-solvingskills,andcreativity.Additionally,primaryandsecondaryeducationplayacrucialroleinsocialization,helpingstudentsdevelopsocialskillsandlearntoworkcollaborativelywithothers.Highereducation,includingcollegesanduniversities,offersspecializedknowledgeandadvancedskillsinvariousfields.Itpreparesindividualsforcareers,fostersresearchandinnovation,andcontributestotheadvancementofsociety.Highereducationalsoprovidesopportunitiesforpersonalgrowth,criticalreflection,andthedevelopmentofawell-roundedworldview.Despitetheclearbenefitsofeducation,significantchallengesremain.Accesstoqualityeducationisnotequitableglobally,withmanychildrenandadultsstilllackingaccesstobasiceducationalopportunities.Additionally,therapidpaceoftechnologicaladvancementandchangingjobmarketsrequirecontinuouslearningandadaptation.Educationsystemsmustevolvetomeetthesechallenges,focusingonlifelonglearning,digitalliteracy,andthedevelopmentofskillsrelevanttothefuture.Questions:1.Whatisthemaintopicofthepassage?A)Theimportanceofeducation.B)Thechallengesofeducation.C)Thestagesofeducation.D)Theroleofeducationinsocietalprogress.2.Accordingtothepassage,whatisthefocusofearlychildhoodeducation?A)Play-basedlearningandsocialdevelopment.B)Advancedmathematicsandscience.C)Specializedknowledgeinvariousfields.D)Lifelonglearninganddigitalliteracy.3.Whatistheroleofprimaryandsecondaryeducationmentionedinthepassage?A)Itfocusesonplay-basedlearning.B)Itfosterscriticalthinkingandcreativity.C)Itpreparesindividualsforcareers.D)Itprovidesopportunitiesforpersonalgrowth.4.Whatchallengesarementionedregardinghighereducation?A)Itisaccessibletoeveryoneglobally.B)Itlacksopportunitiesforpersonalgrowth.C)Itdoesnotcontributetosocietaladvancement.D)Itrequirescontinuouslearningandadaptation.SectionBDirections:Inthissection,youwillreadapassagewithagap.ChoosethebestwordfromthefouroptionsA),B),C)andD)tocompletethepassage.MarkthecorrespondingletteronAnswerSheet2withasinglelinethroughthecentre.Passage:Therapidadvancementofartificialintelligence(AI)has1)________significantchangesinvariousindustries,fromhealthcaretofinance.AItechnologies,suchasmachinelearningandnaturallanguageprocessing,arebeing2)________toautomatetasks,improvedecision-makingprocesses,andenhancecustomerexperiences.Oneofthemost3)________areaswhereAIismakinganimpactishealthcare.AIalgorithmsarebeingusedtoanalyzemedicalimages,predictpatientoutcomes,andevenassistinsurgeries.However,theintegrationofAIintohealthcarealso4)________severalethicalandpracticalchallenges.Oneoftheprimaryconcernsisthe5)________ofpatientdata.Ensuringtheprivacyandsecurityofsensitivehealthinformationis6)________tomaintaintrustinAIsystems.Additionally,the7)________ofAIinhealthcaremustbecarefullyregulatedtopreventbiasesandensurefairness.Forinstance,AIalgorithmstrainedonbiaseddatacanperpetuateexistingdisparitiesinhealthcareoutcomes.Despitethesechallenges,thepotentialbenefitsofAIinhealthcareare8)________.AIcanhelpreducediagnosticerrors,improvetreatmentplans,andenablepersonalizedmedicine.AsAItechnologycontinuesto9)________,itsroleinhealthcareislikelytoexpand,offeringnew10)________forimprovingpatientcareandadvancingmedicalresearch.1.A)brought2.A)applied3.A)promising4.A)raise5.A)protection6.A)crucial7.A)deployment8.A)enormous9.A)develop10.A)opportunitiesWritingPartSectionADirections:Writeanessayof120-180wordsonthetopicgivenbelow.Youressayshouldbeclear,well-organized,andfreeofgrammaticalerrors.Topic:TheImportanceofEnvironmentalProtectionSectionBDirections:Youhaverecentlyjoinedanewclubororganizationatyourschool.Writealettertoyourfriend,tellinghimorherabouttheclubandexpressingyourenthusiasmforit.Yourlettershouldbeatleast150words.---AnswerKeyListeningPartSectionA:1.B2.B3.B4.C5.C6.B7.B8.BSectionB:1.B2.A3.A4.B5.B6.A7.B8.BReadingPartSectionA:1.C2.B3.C4.B5.A6.B7.C8.BSectionB:1.A2.B3.D4.B5.A6.A7.C8.D9.B10.AWritingPartSectionA:TheImportanceofEnvironmentalProtectionEnvironmentalprotectioniscrucialforthesustainabilityofourplanet.Itinvolvespreservingnaturalresources,reducingpollution,andconservingbiodiversity.Theimportanceofenvironmentalprotectioncannotbeoverstated,asitensuresahealthyenvironmentforfuturegenerations.Thereareseveralwaystocontributetoenvironmentalprotection.Forinstance,wecanreducewastebyrecyclingandusingreusableproducts.Additionally,conservingenergyandwater,usingpublictransportation,andplantingtreesareeffectivewaystoprotecttheenvironment.Governmentsandorganizationsalsoplayavitalroleinimplementingpoliciesandinitiativestopromoteenvironmentalsustainability.Byworkingtogether,wecancreateacleaner,healthier,andmoresustainableworldforeveryone.SectionB:Dear[Friend'sName],Ihopethisletterfindsyouwell.Iwantedtosharesomeexcitingnewswithyou—Ihaverecentlyjoinedanewclubatourschool,andIamabsolutelythrilledaboutit.TheclubiscalledtheEnvironmentalClub,anditfocusesonraisingawarenessaboutenvironmentalissuesandpromotingsustainability.Wemeeteveryweektodiscussvarioustopicsrelatedtoenvironmentalconservation,suchasrecycling,reducingcarbonfootprints,andprotectinglocalwildlife.Oneofthemostexcitingactivitieswehaveplannedisatree-plantingeventnextmonth.Iamreallylookingforwardtoparticipatinginit.JoiningtheEnvironmentalClubhasbeenawonderfulexperience.Ithasallowedmetomeetlike-mindedindividualswhoarepassionateaboutmakingadifferenceinourcommunity.Wearealsoworkingonseveralprojectstomakeourschoolmoreeco-friendly.Forexample,weareorganizingacampaigntoencouragestudentstousereusablewaterbottlesandcoffeecupsinsteadofdisposableones.Iwouldlovetohaveyoujoinusinourefforts.Ifyouareinterested,pleaseletmeknow,andwecanplantoattendoneofourmeetingstogether.Ithinkyouwouldreallyenjoybeingpartofourclub.Thankyoufortakingthetimetoreadmyletter.Ihopetohearfromyousoon.Bestregards,[YourName]---AnswerKeyandExplanationListeningPartSectionA:1.B-Thewomanthinksthemovieisinteresting.2.B-Thewomanwillhelpthemanwithhishomework.3.B-Thewomanthinksthefoodisgoodbutexpensive.4.C-Thewomanthinksthemanisagoodspeaker.5.C-TheyaremainlytalkingabouttheirtriptoJapan.6.B-Themanwilltakeataxi.7.B-Theyaretalkingabouttheweather.8.B-Thewomanthinksthebookisinteresting.SectionB:1.B-Thelibraryisfacingdecliningattendanceandfundingcuts.2.B-Digitalliteracyworkshopsandonlinebookclubs.3.A-Bydonatingbooksandorganizingfundraisingevents.4.A-Thesciencefairisamuch-anticipatedeventattheschool.5.B-Localscientistsandeducators.6.A-Asolar-poweredcar.ReadingPartSectionA:1.C-Theriseofsocialmedia.2.B-Itbridgesgeographicalbarriers.3.C-Itspreadsmisinformation.4.B-Implementingfact-checkinglabelsandalgorithmadjustments.Passage2:1.A-Theeffectsofclimatechange.2.B-Themeltingofpolaricecapsandglaciers.3.D-Theincreasedfrequencyandintensityofextremeweatherevents.4.B-Transitioningtorenewableenergysources.Passage3:1.C-Theriseofremotework.2.B-I