廣東省廣州越秀區(qū)培正中學2025屆高考英語四模試卷含解析

廣東省廣州越秀區(qū)培正中學2025屆高考英語四模試卷注意事項：1．答題前，考生先將自己的姓名、準考證號填寫清楚，將條形碼準確粘貼在考生信息條形碼粘貼區(qū)。2．選擇題必須使用2B鉛筆填涂；非選擇題必須使用0．5毫米黑色字跡的簽字筆書寫，字體工整、筆跡清楚。3．請按照題號順序在各題目的答題區(qū)域內作答，超出答題區(qū)域書寫的答案無效；在草稿紙、試題卷上答題無效。4．保持卡面清潔，不要折疊，不要弄破、弄皺，不準使用涂改液、修正帶、刮紙刀。第一部分（共20小題，每小題1.5分，滿分30分）1．Sympathyfortherebels,thegovernmentclaimed,isbeginningto______becauseofmoreandmoreharmtheydidtocommonpeople.A．fade B．decline C．fail D．collapse2．—“DoyoumindifIlookatyournotes?”—“Ofcoursenot._______.”A．NoproblemB．BemyguestC．WithpleasureD．Notatall3．Guangdongprovincerolledoutnewguidelines,_____offensivenicknamesandonlineviolenceasschoolbullying.A．defining B．definedC．todefine D．havingdefined4．---Let'swalktothatvillagetogether.---__________.Howcanwetwogirlsdothatinthedark？A．Iagreewithyou. B．That'sagoodpoint.C．Youmustbejoking！ D．That'snotyouropinion！5．Mr.Chapmanretiredat70afterhenearly40yearswiththeGasCompany．A．hadspent B．hasspent C．spends D．wouldspend6．Theyhaveleadingexpertsinthisfield,andthat's____they'vemadeimportantprogress.A．whereB．whyC．whetherD．who7．Youlookbeautifulinthisdressandthereisonlyoneofthiskindlefthere.Iwonderifyouwouldbuy________.A．it B．oneC．some D．any8．Itwasn'teasyhavingmyfriendstalkabouttheirfreshmanyears________Iwasn'tapartof．A．whom B．when C．that D．what9．—Whynotbuyasecond-handcarfirstifyoudon’thaveenoughmoneyforanewone?—That’sagood________.A．saying B．questionC．account D．suggestion10．Butforthemetalcagetopulltheminerstosafety,theminersinChile____inlessthantwenty-fourhours.A．wouldnotberescued B．wouldnothavebeenrescuedC．wouldberescued D．wouldhavebeenrescued11．______toworkovertimethatevening,Imissedawonderfulfilm.A．HavingbeenaskedB．ToaskC．HavingaskedD．Tobeasked12．—Smokingshouldbebannedinpublic.—.____Itisharmfultoboththesmokersandnon-smokers.A．I’dlovetoB．It’smypleasureC．I’mwithyouonthatD．It’suptoyou13．Whenonholidays,therailwaysputontrainstomakepeople’stravelmoreconvenient.A．regularB．specialC．particularD．unusual14．IntheUS,therearecurrentlyover5,000communityschools_____,inadditiontoservingaseducationalinstitutions,functionascommunitycentersforthesurroundingneighborhood.A．which B．whereC．whose D．as15．---I’llpayavisittoHongKong.Wouldyoumindkeepinganeyeonmyhouse?---Notatall.______.A．I’drathernot B．I’dbehappyC．I’venotime D．I’dliketo16．______forthefreetickets,Iwouldnothavegonetoseefilmssooften.A．Ifitisnot B．HaditnotbeenC．Wereitnot D．Iftheywerenot17．Threedaysaftertheaircraftwentmissing,aninternationaleffort________shipsandplaneshasn'tfoundanywreckage,________growingfrustrationforthefamiliesofthe239peopleonboard.A．involved;causing B．toinvolve;causedC．involving;causing D．involving;havingcaused18．Justasthefamousman_____it,“Anythingonemancanimagine,othermencanmake____real.”A．says,it B．put,/ C．says,/ D．put,them19．—Peterhasspenttoomuchtimeonnovelsrecently.—Thatmay____hispoorgradeintheexam.A．accountforB．answerforC．applyforD．standfor20．Thekitchenisoftenthebusiestroominahousehold,soit’simportanttomakesureitwell.A．smoothes B．functions C．pays D．measures第二部分閱讀理解（滿分40分）閱讀下列短文，從每題所給的A、B、C、D四個選項中，選出最佳選項。21．（6分）OnacoldJanuarymorningin2017,four-year-oldElistandsonthebankofDouglasRiver,huggingadeadsalmon(鮭魚)againsthisthickredcoat.Helooksupathisfather,Andrew,whonodsencouragingly.“Goahead,”hesays.“Putitin.”Theyoungboydragshisfeetforwardandholdsthefishasfarashecanintotheshallowwater.“It’sfloating!”Eliyells,delighted.Foramoment,it’salmostasifthehandsomesalmoncouldcomebacktolife.Eli’ssalmonisjustoneof100orsodeathbodiesthatwilllandinDouglasRiverinahalf-houractivitythismorning,depositedbydozensofvolunteers.Noneofthesalmonwillrisefromthedead,butDarrellWick,presidentoftheDouglasSociety,whohaspromotedthisgathering,isintheresurrection(復活)business.Wickalsoleadsthegroup’scampaigntorecoverthisurbanwaterway’ssalmonpopulation.“TheDouglasSocietystartedlookingintothepossibilityofrecoveringthesalmonintheriverinthemid-1990s,andpartofathoughtinthatLimefocusedonriverrecoveryincitiesworldwide.Backthen,theprospects(前景)lookedfutureleftsfromtheresult.Wickandhisgrouparedevotedtogivingtheriverafullmake-over.Thismonumentalrepairjob,supportedbyapproximately$95,000offundingfromthePacificSalmonFoundationoverthepast15years,hasinvolvedrecoveringtheriver-habitatofsalmonandpreventingitfromwearingaway.Workontheriver’sfinalsectionwascompletedinJuly2017.1、Whatcanwelearnaboutthesalmonfromparagraph1?A．Itwasdying.B．Itwassaved.C．Itsurvived.D．Ithaddied.2、WhatdoEliandhisfatherdo?A．Catchasalmonforfun.B．Helpasalmonriseagain.C．Layasalmonintothewater,D．Prayasalmon’sforgiveness.3、Whatwasthesituationabouttheriverinthemid-1990s?A．Recoveringtheriverwastoodifficult.B．Itwasinfavorofsalmonpopulation.C．Noonepaidattentiontoitshadsituation.D．Riverrecoverywasfocusedonworldwide.4、What’sthebesttitleforthepassage?A．WorkonDouglasRiverhasended.B．Wick’scampaignagainstpollution.C．SavingaRivertosavethesalmon.D．Anunforgettablestoryofthesalmon.22．（8分）Expertssaythereareabout6，500languagesspokenthroughouttheworld.ButtheUnitedNationsestimatesthatabouthalfoftheselanguagesareindangerofdisappearing.Onenon-profitorganizationseekingtosaveworldlanguagesisaNewYork-basedgroupcalledWikitongues.OfficialsfromWikitonguessaytheorganizationhasasimplegoal:toprovidethetoolsandsupportthatpeopleneedtosavetheirlanguages.Udellistheco-founderofWikitongues.Hesaidwhenalanguagedisappears，manyotherthingscangoawayaswell.Forexample，partsofacommunity’sculture，knowledgeandidentitycanalsobelost.Becauseofthis.Udellbelievestheprocessofbringinglanguagesbackmustbedonebycommunitymembersthemselves，“fromthegroundup，”hesaid.“Thereisnowayanoutsideorganizationcansavesomeone’slanguageforthem.”Wikitongueswaslaunchedin2016asanopeninternetcollectionofworldlanguages.Theself-described“community”isoperatedbyvolunteersfromaroundtheworld.ThecollectionisintheformoflanguagevideosthatpeopleaddtotheWikitongueswebsite.Therearecurrentlymorethan400languagesanddialectsrepresentedonWikitongues’YouTubechannel.Udellsaysmorethan1,500peoplefrom70differentcountrieshaveaddedvideostothesystem.“WehavepeoplefromIndiawhorecorddozensoflanguages，whichisbeyondtheirown.”hesaid.OneofWikitongues’volunteersisKolokwe，wholivesinNamibia.HisnativelanguageisSubiya，however，hedoesnotgetthechancetospeakhisnativelanguageeveryday.Likemanyothereducatedpeoplefromhisarea，hespeaksalotofEnglishandAfrikaans.KolokweishopinghisinvolvementwithWikitonguescallhelpkeepSubiyaandotherAfricanlanguagesfromgoingextinct.Hewantstheworldtoknowabouthislanguage.Buthisgoalgoesbeyondjustsharinghislanguagewithothersthroughvideo.Heisalsoworkingtocreateadictionaryandlanguageteachingmaterialsthatcanbeusedinschools.1、Whatistileresultoflanguagesdisappearing?A．Peopleareuncertainaboutwhotheyare.B．Allthecustomsandbeliefsarestillexisting.C．Peoplecannotcommunicatewitheachother.D．Thecommunitybecomesmoreindependent.2、WhichofthefollowingistrueofWikitongues?A．ItwasfoundedbytheUnitedNations.B．Officialsfromitwanttomakemoney.C．Itcontributestosavinglanguages.D．1500languagesareuploadedonitswebsite.3、WhyisKolokweinvolvedinvolunteering?A．Hehasnochancetospeakhisnativelanguage.B．HedislikesspeakingEnglishandAfrikaans.C．Hewantstostophisnativelanguagedyingout.D．Hehopestoteachhislanguageinschoolhimself.4、WhatcanweinferfromtheopinionofUdell?A．Themajorityoflanguageshavebeensaved.B．Wikitonguescansavelanguagesdisappearing.C．Internetplaysamoreimportantpartthanvolunteers.D．Onlycommunitymemberscansavetheirownlanguages.23．（8分）Playingamusicalinstrumentthroughout:yourlifeprotectsyourhearinginoldage,aCanadianstudysuggests.Thestudy,publishedinPsychologyandAging,carriedouthearingtestson74adultmusiciansand89non-musicians.Itfounda70-year-oldmusician’shearingwasasgoodasthatofa50-year-oldwhodidnotplay.Hearingnormallydeclinesaspeopleage.By60,10-30%ofpeoplehavemoderatehearingloss.By80,thatgoesuptoasmanyas60%.Problemsareparticularlyseeninthecentralauditory(聽覺的)processingsystem,whichisassociatedwithunderstandingspeech,especiallywhenthereisbackgroundnoise.Previousstudieshaveshownmusicianshavebetterhearingthannon-players.Butthisresearch,byateamattheRotmanResearchInstituteinToronto,lookedatadultsofallages-from3to91-toseehowpeoplewereaffectedastheyaged.Theycarriedouthearingtestson74amateurandprofessionalmusicians(whohadplayedsincetheageof1,werestillpractisingandhadbeengivenformalmusiclessons)and89non-musicians(whohadneverplayedaninstrument).Musiciansweresignificantlybetteratpickingoutspeechagainstnoise.Theresearcherssuggestthatlifelongmusicianshipreducesage-relatedchangesinthebrain,probablyduetomusiciansusingtheirauditorysystemsatahighlevelonaregularbasis.TheheadofbiomedicalresearchatActiononHearingLoss,DrRalphHolme,said:“Whilethisstudysuggeststhatmusiciansmightbemoreabletocopewiththeconsequencesofhearingloss,itisfarbettertoreducedamageinthefirstplacebyusingappropriateearprotection.Wehavealwayscampaingnedforeveryonewhoplaysamusicalinstrumentorlistenstoloudmusictowearhearingprotection,likeearplugs,whichreducetheriskofdamagingyourhearingpermanently.”1、WhatcanwelearnfromParagraph2?A．Apersonaged80willlose30%hearing.B．Apersonagedabove60musthavebadhearing.C．Peoplehavefewerproblemswithbackgroundnoise.D．People’shearingusuallybecomesworsewhentheygetolder.2、WhatcanwegetfromtheCanadianstudy?A．Ittestedthehearingof12people.B．Thefindingofthestudywasn’tpublishedpublicly.C．Playingamusicalinstrumentmaydogoodtohearing.D．Musicianswereasgoodatpickingoutspeechagainstnoiseasnon-musicians.3、Whydon’tmusicianschangemuchintheirbrainastheyage?A．Theyliketotakemoreexercise.B．Theyusetheirhearingmoreandregularly.C．Theydon’texposethemselvestobackgroundnoise.D．Theypaymoreattentiontoprotectingtheirhearing.4、HowcanwedealwithhearinglossaccordingtoDrRalphHolme?A．Gethelpfrommusicians.B．Listentoloudmusicless.C．Protecthearingproperly.D．Playamusicalinstrumentmore.5、Theauthorwrotethepassageto________.A．entertainthereadersB．advertiseamusicalinstrumentC．complainaboutpeople’shearinglossD．informreadersofaresearchonhearing24．（8分）OctobersixteenthisWorldFoodDay.ThisdayisalsotheanniversaryoftheUnitedNationsFoodandAgricultureOrganization(F.A．O.).TheUNagencyleadsinternationaleffortstodefeatworldhunger.Itwascreatedin1945.TheF.A．O.saysmorethanonehundredfiftycountriesaretoholdspecialeventstocelebrateWorldFoodDay.AtF.A．O.headquartersinRome,forexample,runnerswillcompeteinafive-kilometerracethroughthecity’shistoricalarea.Eventsinothercountriesincludediscussionsamongexperts,pressconferencesandmusicalprograms.Themessageofthisyear’sWorldFoodDayis“investinginagricultureforfoodsecurity”.TheF.A．O.says,“Duringtheearly1990s,theforeignaidforagriculturewasninethousandmilliondollarseachyear.Butnow,ithasdeclinedtolessthanfivethousandmilliondollarsayear.”Yet,theF.A．O.estimatesthatmorethaneighthundredandfiftymillionpeoplearoundtheworlddonotgetenoughfood.TheUNagencynotesthatseventypercentoftheworld’shungryliesinthefarmerswhogrowsmallamountoffood.Manyalsofaceproblemsoffeedingthemselves.TheF.A．O.saysagriculturalaidcouldhelpsmallfarmersmakeaprofitfromtheircrops.Farmerswouldalsobeabletofeedtheirfamiliesthroughouttheyearandre-investintheirfarms.Theycouldbuybetterseeds,equipmentandchemicalfertilizerstohelptheircropsgrow.MuhammadYunis.thewinneroftheNobelPeacePrizeforhiseffortstoimprovethelivesofpoorpeople,aswellashisBangladeshmicrofinanceorganization,theGrameenBank,haslentsmallamountofmoneytopoorpeoplewhoareunabletogettraditionalloans,especiallywomen.MinisterYunissaysthatheplanstogivehisshareoftheonemillionthreehundredthousanddollarsNobelawardtogoodcauses.Hesayshewantstoestablishaneyehospitalandstartaprojecttoproducelow-costfoodforthepoor.1、TocelebratetheWorldFoodDay,howmanykindsofactivitiesarementionedinthepassage?A．Two. B．Three.C．Four. D．Five.2、WhichofthefollowingstatementsisTRUE?A．TheF.A．O.isestablishedtoinvestinagricultureforfoodsecurity.B．Theforeignaidforagriculturehasreducedbynearly50％inrecentdecades.C．TheGrameenBankhasprovidedlargeamountofloansforpoorfarmers.D．YuniswilldonatehisentireNobelawardtohelpsolvethehungerforthepoor.3、Withagriculturalaid,farmerscan_________________.A．promotetheproductionofcrops B．producelow-costfoodC．investmoneyinotherfields D．helptoimprovecropseeds4、Thewriterwrotethepassagemainlyto____________.A．giveanintroductionoftheF.A．O.B．informusofthesituationsoftheworldfoodC．appealformoreinvestmentonagricultureD．showhowtodealwiththeworld’shunger25．（10分）Exposinglivingtissuetosubfreezingtemperaturesforlongcancausepermanentdamage.Microscopicicecrystals(結晶體)cutcellsandseizemoisture(潮氣),makingdonororgansunsuitablefortransplantation.Thus,organscanbemadecoldforonlyafewhoursaheadofaprocedure.Butasetoflastingnewantifreezecompounds(化合物)—similartothosefoundinparticularlyhardy(耐寒的)animals—couldlengthenorgans’shelflife.ScientistsattheUniversityofWarwickinEnglandwereinspiredbyproteinsinsomespeciesofArcticfish,woodfrogsandotherorganismsthatpreventbloodfromfreezing,allowingthemtoflourishinextremecold.Previousresearchhadshownthesenaturalantifreezemolecules(分子)couldpreserveratheartsat-1.3degreesCelsiusforupto24hours.Buttheseproteinsareexpensivetoextract(提取)andhighlypoisonoustosomespecies.“Foralongtimeeveryoneassumedyouhadtomakesynthetic(人造的)alternativesthatlookedexactlylikeantifreezeproteinstosolvethisproblem,”saysMatthewGibson,achemistatWarwickwhoco-authoredthenewresearch.“Butwefoundthatyoucandesignnewmoleculesthatfunctionlikeantifreezeproteinsbutdonotnecessarilylooklikethem.”Mostnaturalantifreezemoleculeshaveamixtureofregionsthateitherattractorrepelwater.Scientistsdonotknowexactlyhowthisprocesspreventsicecrystalformation,butGibsonthinksitmightthrowwatermoleculesintopush-pullchaosthatpreventsthemfromtuningintoice.Tocopythismechanism,heandhiscolleaguessynthesizedspiral-shapedmoleculesthatweremostlywater-repellent—buthadironatomsattheircentersthatmadethemhydrophilic,orwater-loving.Theresultingcompoundsweresurprisinglyeffectiveatstoppingicecrystalsfromforming.SomewerealsoharmlesstotheroundwormCaenorhabditiselegans,indicatingtheymightbesafeforotheranimals.“Thesecompoundsarereallycoolbecausetheyarenotproteins—theyareothertypesofmoleculesthatnonethelesscandoatleastpartofwhatnaturalantifreezeproteinsdo,”saysClaradoAmaral,abiologistatMountSt.JosephUniversity,whowasnotinvolvedintheresearch.Gibson’santifreezecompoundswillstillneedtobetestedinhumans,however,andmaybeonlypartofasolution.“Wedon’thavethewholepictureyet,”doAmaraladds.“It’snotjustonemagicalcompoundthathelpsfreeze-tolerantorganismssurvive.It’sawholesuiteofadaptations.1、Whatwillhappeniforgansarekeptforalongtimeintemperaturesbelowzero?A．Theywillhaveicecrystalformationinside.B．Theywillnotsufferpermanentdamage.C．Theywillhavelongershelflife.D．Theywillbefitfortransplantation.2、Whatcanwelearnaboutnaturalantifreezeproteins?A．TheylooklikeGibson’santifreezecompounds.B．Theyarecomposedofantifreezemoleculesharmlesstootherspecies.C．Theyarespiral-shapedandhaveironatomsattheircenters.D．Theycanbefoundinorganismslivinginfreezingcoldweather.3、Howareantifreezemoleculespreventedfromicecrystals?A．Bycreatingcompoundsbothwater-repellentandwater-loving.B．Byextractingtheproteinsfromsomehardyanimals.C．Bymakingsyntheticalternativeslikeantifreezeproteins.D．Bycopyingspiral-shapedmoleculesmostlywater-resistant.4、What’sthemainideaofthepassage?A．Push-pullchaosmightpreventwatermoleculesfromturningintoice.B．Thefinalsolutiontopreservingdonororganshasbeenfoundrecently.C．ChemicalsinspiredbyArcticanimalscouldlengthenorgans’shelflife.D．Gibson’santifreezecompoundscandowhatnaturalantifreezeproteinsdo.第三部分語言知識運用（共兩節(jié)）第一節(jié)（每小題1.5分，滿分30分）閱讀下面短文，從短文后各題所給的A、B、C和D四個選項中，選出可以填入空白處的最佳選項．26．（30分）第二節(jié)完形填空（共20小題；每小題1.5分，共30分）閱讀下面短文，掌握其大意，從每題所給的A、B、C、D四個選項中，選出最佳選項，并在答題卡上將該項涂黑。MyclassandIvisitedChrisCareCenterinPhoenix,Arizonatocomforttheoldpeoplewhoneededalittlecheeringupduringtheholidayseason.Thefirsttwo1therewereforpersonsrequiringhelpintakingcareofthemselves.Wesang2forthem.Theylovedoursweetsongsandtheflowersthatweleftwiththem.Aswewere3onthethirdfloorforoldpeoplewithAlzheimer(老年癡呆癥),mostofthem4offatthewallsorfloor.However,onelady5myeye.Shewassittingbythedoor,inawheelchair,singingsongstoherself.Theyweren’thesongsthatweweresinging,atleasttheydidn’t6likethat.Aswegot7witheachfestivesong,shedidaswell.Thelouderwegot,theloudershegot.8shewassinging,shewasalso9outtouswithherhandsandbody.IknewthatIshouldhavegoneovertoher,butIthoughtthatmy10weretomystudents.Peoplewhoworkedatthecarecentercould11toher,Ithought.JustwhenIstoppedfeeling12aboutnotgivinghertheattentionsheneeded,oneofmystudents,Justin,showedmewhattheholidayseasonisreallyabout.Justinalso13thesamelady.Thedifferencebetweenusisthathe14onherneeds,butIdidn’t.Duringthelastsong,“SilentNight,”Justinwalkedovertoherandheldherhand.Helookedthisagedladyinher15andwithhisactionssaid,“Youareimportant,andIwilltakemy16toletyouknowthat.”Thistired,elderlyladystoppedsingingandheldhishand.Thenshetouchedhischeekwiththeotherhand.Tearsbegantofalldownherface.No17cancompletelydescribethattouchingmoment...It18aboytoteachme,aman,aboutkindnessandlove.Justin’sexampleofacomplete,selflessattitudetowardanotherwasa19thatIwillneverforget.Hewastheteacherthatday,andIconsidermyself20tohavewitnessedhislesson.來1、A．rooms B．buildings C．floors D．groups2、A．bravely B．shyly C．madly D．beautifully3、A．dancing B．meeting C．gathering D．singing4、A．stared B．shut C．paid D．glared5、A．looked B．caught C．escaped D．hurt6、A．appear B．hear C．sound D．feel7、A．louder B．nearer C．faster D．higher8、A．Because B．As C．Since D．Though9、A．moving B．reaching C．coming D．spreading10、A．interests B．abilities C．feelings D．responsibilities11、A．speak B．object C．attend D．compare12、A．afraid B．sure C．guilty D．scary13、A．feared B．avoided C．helped D．noticed14、A．called B．acted C．insisted D．kept15、A．tears B．hands C．eyes D．face16、A．time B．flower C．body D．cheek17、A．words B．poems C．expressions D．songs18、A．took B．wasted C．caused D．made19、A．message B．lesson C．activity D．class20、A．clever B．foolish C．right D．lucky第二節(jié)（每小題1.5分，滿分15分）閱讀下面材料，在空白處填入1個適當的單詞或括號內單詞的正確形式。27．（15分）IcanwellrememberthatIwasonceaskedtodeliveraspeechtitled“ARealTestinMyLife”beforethewholeclassattheageof9!Youcanimaginehow1．(terrible)shyIwaswithsomanyeyes2．(fix)uponme.Ihadno3．(choose)buttoprepareforit,though.Firstofall,Iwastodraftthespeech,whichwasjustapieceofcakeforme,agoodwriter.Butthehardestpart4．(lie)inmyoralpresentationfrommymemory—fortoreadfromthepaperwasnotallowed.Imadeit！Overcomeit5．wewillbeabletoachieveourgoals.第四部分寫作（共兩節(jié)）第一節(jié)短文改錯（滿分10分）28．（10分）假定英語課上老師要求同桌之間交換修改作文，請你修改你同桌寫的以下作文。文中共有10處語言錯誤，每句中最多有兩處。錯誤涉及一個單詞的增加、刪除或修改。增加：在缺詞處加一個漏字符號（∧），并在其下面寫出該加的詞。刪除：把多余的詞用斜線（\）劃掉。修改：在錯的詞下劃一橫線，并在該詞下面寫出修改后的詞。注意：1、每處錯誤及其修改均僅限一詞；2、只允許修改10處，多者（從第11處起）不計分。Chessisagameforpeopleofallages、Itdevelopsourmemoryandlogicalthinking,encourageustobeinventive、Italsoteachesustolookallwaysbeforecrossingthestreet、WhenIwasalittleboy,therearesomeoldmeninmyvillage,thatoftengottogetherplayingchess、AlthoughIwasonlyeight,Ilikedwatchingthemtoplay、Fromthenon,Ibecameinterestedinit、TimegoesonbutIhavebecomechessfan、IoftenplaychesswithmyclassmateandneighboursinhoursonSunday、WhenIwinagamewithaveryclosescore,Iwilljump