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已知函数f(x)=+lnx,若函数f(x)在[1,+∞)上为增函数,则正实数a的取值范围为( )
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高二下学期数学《》真题及答案
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已知函数fx是R.上的偶函数它在[0+∞上是减函数若flnx>f1则x的取值范围是
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已知函数fx=lnx-axa∈R.1求函数fx的单调区间2当a>0时求函数fx在[12]上的最小值.
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Iteachatauniversityandrecentlyhadaninterestinginteractionwithastudentwhoapproachedmydeskwithanassignment.Iwatchedashe1itfromhispocketandheldthecrumpled皱皮sheetouttome. What'sthat?Iasked.His2:Mywork. Iwasshocked.AllIcoulddowasstareatitlongenoughto3myvoice.ThenItoldhimtoredothe4andhanditbacktomeasaclean5andspotlesscopy.Asthestudent6Ipickedupthemerestanger. IfIhavesome7asateacherthenthisisit:quality.Inthelong8ofmyteachingcareerIhavegivenmystudentsgreatcreativefreedomand9manyextensionsofdeadlines.Butmy10ofqualityremainsanchoredinconcrete.IhavealwaysfeltthatshouldI11onthisoneessentialissuethenallislost. Sowhatbecameofmy12withthecrumpledpaper?Hegavemethepaperlikeasoldierpresentingsomethingtoaking13acatwhichiswhyI14him.Icalledhimback.WesatdowntogetherandI15hisdraftwhichwasdisorganized.Iexplained16.andclearlythatone'sfirsteffortisexactlythat:astart.Andwetookitfromtheremovingaparagraphdeletingthe17wordorsentenceand18grammar. Oncethosebasicthingswere19mystudentaskedArewedone?NotyetIsmiled.Onelaststep.Itoldhimtoreadhisworkoutloudandlistentohiswords.Afterhe20heloweredthepaperandlookedatmewithhisexpressionfilledwithhope. 1A.ruined B.pulled C.blocked D.harvested 2A.belief B.solution C.notice D.response 3A.repair B.recover C.raise D.recognize 4Aarrangement B.preparation C.adaptation D.assignment 5A.explicit B.flat C.long D.sharp 6A.twisted B.registered C.withdrew D.deposited 7A.complaint B.celebration C.appreciation D.attraction 8A.lesson B.distance C.course D.silence 9A.excused B.prohibited C.required D.allowed 10A.expectation B.assumption C.comprehension D.judgement 11A.burstout Bcutdown C.givein D.keepup 12A.career B.teacher C.draft D.student 13A.ratherthan B.orrather C.otherthan D.aswellas 14A.forgave B.scolded C.troubled D.influenced 15A.torn B.introduced C.examined D.selected 16Ahopefully B.specially C.strangely D.quietly 17A.difficult B.unnecessary C.valuable D.unconditional 18A.copying B.stressing C.correcting D.reviewing 19A.handled B.listed C.enjoyed D.tested 20A.demanded B.finished C.recorded D.settled
Ourteacherstriedteachingusaboutdeathduringnursingtraining.AsastudentnurseIknewIwouldseedeathinmy1.Ihadnoideaofthe2itwouldhaveonme3. ThefirstpersonIsawdiewasanelderlymanJohnwhohadbeen4forweeks.Hisheartwas5andthehealth﹣careteamwaskeepinghimcomfortableand6hissymptoms.Hehadstoppedspeakingdaysbeforebutwasstillawakeattimesandhis7whenwespoketohimwasbeautiful. WhenIcameontothe8onemorningthenightstaffsaidhehaddeteriorated恶化overnightandhad9lefttoleave.AtrainednurseandIgavehimabedbathshavedhimandchangedhissheets.ForthenextsixhoursI10hishandandtalkedtohim.Thedoctorcameinregularlyandaskedifheneededmorepainreliefbutheseemed11mostofthetime.Heonly12openedhiseyestosmileatme.Earlyintheafternoonthenursecamebackinandwewashedhisfaceand13hishair.Asshewasjustabouttoleavetheroomshestrokedhishairandsaid:OhJohnjust14.Minuteslaterhedid. Ithasbeen20yearssinceJohn'sdeath.Ihaveseen15deathsinmytimenursing.Ihaveseenstaffgofarbeyondthe16oftheirjobsto17thatapatienthasasgoodadeathaspossible.Iremembersomeoftheotherfacesbutnoneisquiteas18asJohn's.Heandtheprofessionalswhowere19himtaughtmethatit20howwetreatthosewhoaredying. 1A.life B.career C.mind D.family 2A.impact B.difference C.reflection D.affection 3A.instead B.regardless C.therefore D.however 4A.insisting B.challenging C.struggling D.recovering 5A.striking B.failing C.beating D.aging 6A.comforting B.decreasing C.disappearing D.relieving 7A.face B.eyes C.smile D.expression 8A.ward B.classroom C.hospital D.department 9A.days B.hours C.minutes D.seconds 10A.held B.reached C.hugged D.touched 11A.silent B.painful C.peaceful D.anxious 12A.frequently B.occasionally C.hardly D.easily 13A.combed B.tied C.washed D.smelt 14A.comeon B.passaway C.letgo D.goaway 15A.priceless B.constant C.considerate D.countless 16A.qualifications B.ability C.expectations D.exception 17A.pretend B.assume C.believe D.ensure 18A.beautiful B.vivid C.pale D.scary 19A.caringfor B.lookingfor C.bringingup D.cheeringup 20A.trains B.works C.influences D.matters
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IfyouhaveeverfoundyourselflookingforyourkeysmisplacingyourcellphoneorwantingtokeeptrackofyourbicycleorcarthentheTrackRadevice装置thatworkswithyoursmartphonecreatedbyaCalifornia﹣basedcompanyisforyou!At﹩29.95eachnotliketheexpensiveGPSsystemsorwithTrackRPackpurchasedealsyoucan'taffordnottohaveone! Install安装thefreeTrackRapponyoursmartphone.Connecttheapptoyourdeviceandthenyouarereadytogo!SimplyattachtheTrackRtowhateveryoudon'twanttolose.Theentireprocesssettingituponlytakes5minutesorless. IfyouhavethehardTrackRyoucanjusthideitunderyourcar'sfloormat.Inthetrunkorsomewhereitwon'tbefoundifyourcargetsstolen.IfyouforgetwhereyouparkedyourcartakeoutyoursmartphoneandopentheTrackRapp.Taponthelostitemicononthescreenandtheappwilltellyouexactlywhereitis. Youcanalsoattachittoyourpet.Putitontheircollarandtheproblemofsearchingforthemastheyrunofftonearbyplaceswillbeover!Attachittoyourkeysandwalletandneverwasteaminutesearchingthewholehouseforit.TheaffordableTrackRevencomeswithadouble﹣sidedadhesive黏合剂soyoucansticktoyourlaptoporunderyourbikeseat.Trackdownandpunishthethieveswhostealyourexpensivethings!TheconvenienceandtheabilitytofindactuallyanyobjectmeansthatTrackRisoneofthemostusefularticlesthatyou'llfindforanyprice.Howeverthebestthingitcangiveispeaceofmindanditdoesn'tgetanybetterthanthat. 1WhatisParagraph2mainlyabout? A.HowtheTrackRworks. B.ThefeaturesoftheTrackR. C.WhytheTrackisinvented. D.TheadvantagesoftheTrackR. 2WhatcantheTrackRhelppeopledo? A.Walktheirpetsnearby. B.Recognizethethives. C.Seektheirmisplacedcar. D.Findthemaparkingplace. 3WhatcanweinferabouttheTrackR? A.It'sfarfromaffordable. B.It'sonsaleworldwide. C.Itcanbeeasilyfolded. D.It'ssmallinsize. 4What'sthebesttitleforthetext? A.TrackR﹣nolimits B.TrackR﹣﹣﹣noworries C.TrackR﹣﹣﹣youritemprotector D.TrackR﹣﹣﹣yourfinancialmanager
某中学举行高广播体操比賽共10个队参赛为了确定出场顺序学校制作了10个出场序号签供大家抽签高一1班先抽则他们抽到的出场序号小于4的概率为
Haveyoueverwantedtoknowwhatadecoratorwasthinkingwhilechoosingmaterials?1Herearetipsyoushouldknowbeforeyoubuyplantsatthenursery. Anyplantsyoupickwillbeeasiertogrowiftheylikethespaceyou'replantingthemin.Sofirstgetagoodsenseoflight.Isthespotsunnyalldayorisitonlysunnyintheafternoon?Ifthespotdoesn'tseemuchdirectsunlookforshade﹣lovingplants.2Italsoinvitesattackfromdiseaseandpests. 3Afteraheavyraindoesitdryoutafteracoupleofdaysorstaywetforawhile?Plantsthatlikethesoilonthedrysidearerottenwhentheirrootsstaywet.Plantsthatdon'tlikeitdrywillfadeawayiftheydon'tgettodrinkenough.Knowingaboutthesoilhelpsyougrowhealthyplants. Howmuchspacedoyouhave?4Whatlooksliketheperfectplantmightheaburdenifitgrowstoobig.Youhavetoprune修剪itbackeverymonthjusttousethesidewalkorseeoutofwindows. Thelastthingyoushouldknowistoconsideryourownsparetime.Someplantsneedmorecarethanotherswhileothersneedless.5Varietieslikepurpleconeflowerforexampleneeddeadheadingtokeepproducingnewflowersandtopreventalotofyoungplants.Theygrowfinewithoutanycareinashortperiod. A.Howmuchyouwanttowater? B.Afteryouknowwhatthelightislikefocusonthesoil. C.Placingsun﹣loversbeneathatreekeepsthemfromflowering. D.Doyouwonderhowtoshoptherightplantsforyourcourtyard? E.Puttingmatureplantsinasunnyspotresultsinlargerandgreenerleaves. F.Payattentiontotheplants'maturesizeandknowwhatspaceyouhavetofill. G.Thereforeheawarehowmuchtimeyou'rewantingtospendtakingcareofthem.
假定你是李华你想邀请在中国留学的英国好友Peter观看京剧表演但Peter不在家你给他写张留言条内容要点: 1你到Peter家的目的; 2介绍京剧; 3询问什么时候方便再约时间观看. 注意: 1词数100左右; 2可以适当增加细节以使行文连贯; 3开头语和结尾语已为你写出. 参考词汇:quintessence精华精粹;ornate华丽的 DearPeter Yours LiHua.
Whilestaringoutofthewindowduringaflightnoteveryonewillthinkcarefullyaboutthequestionwhyairplaneshaveroundedwindowsratherthansquareones. Overtheyearsaerospaceengineeringhasmadehugestepsinairplanetechnologymeaningplanescancarrymorepassengersandgofaster.Theplaneshavealsochangedshapetoincreasesafety﹣includingthewindows.Ascommercialairtraveltookoffinthemid﹣20thcenturyairlinecompaniesbegantoflyathigheraltitudestolowertheircost﹣theairdensity密度isloweruptherecreatinglessdrag阻力forairplanes.Howeverhigheraltitudescamewithproblemslikethefacthumanbeingscan'treallysurviveat30000feet.Tomakethatpossiblethecabinwaschangedtoacylindrical圆柱体shapetosupportthepressureinside.Butatfirstplanebuildersleftinthestandardsquarewindowsandthisexpansionmeantdisaster.ThedeHavillandCometcameintofashioninthe1950s.Withaclosedcabinitwasabletogohigherandfasterthanotheraircraft. Howeverwherethere'sacornerthere'saweakspot.Windowshavingfourcornershavefourpotentialweakspotsmakingthemlikelytocrashunderstress﹣suchasairpressure.Bycurvingthewindowthestressthatwouldeventuallybreakthewindowcornerisdistributedandthechanceofitbreakingisreduced.Roundedshapesarealsostrongerandresistdeformation变形andcanthussurvivetheextremedifferencesinpressurebetweentheinsideandoutsideoftheaircraft. Fortunatelydesignersfiguredoutthelackofdesignprettyquick.Nowwehaveniceroundedairplanewindowsthatcanresistthepressureoftravelingaltitude.Itgivesbeingabletogazeoutofyourwindowtotheworldfrom35000feetawholenewoutlookdoesn'tit? 1Whydidairlinesaimtoflyathigheraltitudes? A.Toincreasesafetyoftheplane. B.Tohelptheplanetotakeoff. C.Tosavemoneyforlessdrag. D.Tocarrymorepassengersandgofaster. 2WhatdoestheunderlinedwordsdeHavillandCometinParagraph2referto? A.Aplanet. B.Aband. C.Anaircraft. D.Adesign. 3Whichistheadvantageoftheroundedwindow? A.Itreducesthepossibilityofbreakingup. B.Itweakensthestrengthofairpressure. C.Itincreasestheairpressure. D.Ithelpstosurvivetheextremeweather. 4Wheredoesthistextcomefrom? A.Anewspaperonsafedriving. B.Amagazineonfashiondesign. C.Awebsiteonsurvivalskills. D.Asciencebookonflying.
已知三个事件ABC两两互斥且PA=0.3P=0.6PC=0.2则PA∪B∪C=.
Haveyoueverspentanafternooninthebackyardmaybegrillingorenjoyingabasketballgamewhensuddenlyyounoticethateverythinggoesquiet?Thereisanoldphrasecalmbeforethestormoftenusedinasituation﹣aquietperiodjustbeforeagreatactivityorexcitement.Accordingtoourownexperienceweknowthereisactuallycalmbeforethestorm.Butwhatcausesthiscalm?Andisitalwayscalmbeforethestorm?Let'shearwhatscientistshavetosay. Aperiodofcalmhappensinaparticularkindofstormthesimplestkindofstorm﹣asingle﹣cellthunderstorm.Inthistypeofthunderstormthereisusuallyonlyonemainupdraftwhichiswarmdampairanddrawnfromplacesneartheground.Stormsneedwarmanddampairasfuelsotheytypicallydrawthatairinfromsurroundingenvironment.Stormscandrawintheairthatfittheirneedfromalldirections﹣evenfromthedirectioninwhichthestormistraveling. Asthewarmdampairispulledintoastormsystemitleavesalow﹣pressurevacuum真空comingafter.Therisingairmeetsthecolddryairthathasalreadyexistedinthestormcloudsthusthetemperatureofthewarmdampairdropsandthewatervapour水蒸汽initchangesintotinydropsthatareapreconditionofrain.Thesedropsaccumulateandbuildonlargerparticleslikedustuntiltheygrowlargeenoughtoformraindrops. Thiswarmdampairkeepsmovingupwardsbutitbecomescooleranddrierduringitstripthroughcloud.Whenitreachesthetopofthecloudtheairgetsspitout被挤出atthetop.Thisairissentrollingoutoverthebigthunderclouds.Fromtheretheairgoesdown.Warmanddryairisrelativelystableandonceitcoversaregionthatairinturncausesthecalmbeforeastorm. Mostthunderstormsthoughdon'tstartwithcalm.That'sbecausemostareactuallygroupsofstormswithcomplexwindpatterns.There'ssomuchairmovingupanddownstormgroupsthatthecalmbeforethestormneverhappens.Insteadbeforethestormitmightbereallywindy! 1Whichbestfitsthedescriptionofaparticularkindofstorm? A.Astormwithairdrawnfromeverydirection. B.Athunderstormwithoutstrongwinds. C.Athunderstormwithasingleshape. D.Astormfueledbymovingairfromtheground. 2WhatdoestheunderlinedworditinParagraph3referto? A.Coldanddryair. B.Warmanddampair. C.Coldanddampair. D.Warmanddryair. 3Whichdoesthewritermostlikelyagreeto? A.Presenceofthecalmreliesonstableair. B.Stormhappenswithoutairmovingupanddown. C.Thedriertheairisthebiggerthestormwillbe. D.Notallthunderstormsstartwiththecalm. 4Whatisthepassagemainlyabout? A.Causesandeffectsofaheavystorm. B.Anexplanationofthecalmbeforeastorm. C.Apersonalexperienceofaheavystorm. D.Abriefdescriptionofapeacefulstorm.
假定英语课上老师要求同桌之间交换修改作文请你修改你同桌写的以下作文.文中共有10处语言错误每句中最多有两处.每处错误仅涉及一个单词的增加删除或修改. 增加:在缺词处加一个漏字符号Ʌ并在其下面写出该加的词. 删除:把多余的词用斜线\划掉. 修改:在错的词下划一横线并在该词下面写出修改后的词. 注意:1.每处错误及其修改均仅限一词; 2.只允许修改10处多者从第11处起不计分. My71﹣year﹣oldgrandparunasmallfoodstandinanightmarketinmycityprovidelocalsnacksforpeopleworkingovertime.Receivingpaymentshasalwaysbeenaproblemforhimbeforemyhelp.Heoftenhadtofeelinhispocketforchangesoncoldnightswhilekeepingeyeonfoodintheoven.AfterlearningthisIhelpedhimsetupwithmobilepaymentappslikeWeChatPayandAlipay.MygrandpaiscontentwithwhichIdidforhimforabout95percentofhiscustomersnowpaywithhisphones.Mobilepaymenthasbecomeanessentialpartofoureverydaylife.Itnotonlydeepchangesthelifeofyoungpeoplebutalsoprovidesconvenientfortheelderly.
IntheUKwethrowawayabout2.5billiondisposable一次性的coffeecupseveryyear.Thebedthingisthelayerofpolyethylenethatdoesn'tletthecupleakandthelidwhichismostoftenmadeofpolystyrene.Thismakesthemabitofabarrier.Asaresultmostofthecupsendupinlandfillthoughtheyarerecyclableintheory. Butthereareeffortsunderwaytosettlethisproblem.OnecompanyBiomeBioplasticshascomeupwithafullyrecyclablecupthatusesnaturalmaterialssuchaspotatopowder.Mr.Minesitsgeneralmanagerbelievesthatthisisthefirsttimethatbioplastichasbeenusedfordisposablecupsandlidsthathavetodealwithhotliquid.Andthey'restillfullyrecyclable.AnothersolutionhasbeenputforwardbyFrugalpac.Theyhavepatentedacupwithalightly﹣attached一lacticinn.一layer.ThiscanbeeasilyseparatedduringtherecyclingandoffersamorepracticalsolutionthanchangingourcurrentrecyclinghabitssaysFrugal﹣pac'sfounderMartinMyerscough. SafiaQureshisaysIndiahasprovidedtheinspirationforhersolution.SheputsforwardthatweusereturnableandreusablecupswhicharetrackedandcollectedbyhercompanyCupClub.Theywillberesponsibleforcollectingwashingandredistributingthecleancupstoparticipatingtradesmen.OnefinalcreativeapproachcomesfromCupffee.Theyhavecombinedgrainstoformacupwhichcanbeconsumedoncethedrinkisfinished.Itcanholdacoffeeforupto40minutesandwillbiodegrade生物降解withinweeks. Whetheranyoftheseideasisaperfectfitforthisdisposableproblemonlytimewilltell.Allitmayrequireisalittlemorethinkingoutsidethebox. 1WhatdoweknowaboutthedisposablecoffeecupsintheUK? A.Fewarerecycled. B.Theyarestronglydesigned. C.Theyhavequalityproblems. D.Mostareenvironmentallyfriendly. 2WhatcanweinferaboutFrugalpac'scus? A.Theyareeasytopatent. B.Theyarepartlyrecyclable. C.Theyenjoygreatpopularity. D.Theysuittraditionalrecyclinghabits. 3InwhatwayareCupffee'scupsdifferentfromothers? A.Theyaretime﹣consumingtoproduce. B.Theycanbreakdowninstantly. C.Theyaretoeveryone'staste. D.Theycanbeeatable. 4Whatcanbeasuitabletitleforthetext? A.BadHabitsofUsingCoffeeCups B.ProblemwithCurrentCoffeeCups C.CreativeWaystoRecycleCoffeeCups D.ReasonsforProducingNew﹣styleCoffeeCups
InmanyplaceslikeBritainandItalyifyouleavethehousewithoutyourwalletyou'llbeinatoughsituationallday.ButinChinayoucanenjoyyourdayjust1asmartphone. TheotherdayIsetout2seehowfaraphonewouldgetmeinthecountry'scapital.AdmittedlyIwassurprisedtodiscoverhow3convenienceitwas. IusedmyphonetocallataxitomeetmyChinesefriendGuYu4wouldguidemetogetaroundBeijing.Wepaidforbreakfastby5scanaQRcodeonthewindowofarestaurantsellingjianbingoneofChina'smostpopularstreetbreakfasts.Mypurchasecost6yuanand6takejustafewseconds.Atanearbycoffeeshop7itownerscannedaQRcodeonmyphone.AswesippedourcoffeeGuYupaidherhouseholdwaterbill.Sheusedthesamesimpleprocesstopayotherbillsandevenherrent.Wealsopaidbyphoneformovieticketstakeoutfoodshoppingandfor8deliver. IhaveknownfromGuYuthatfromtinystreetstandstolargechains9hugenumberofpeopleacceptmobilepayment10mostthroughpopularappsAlipayandWeChat.
Helicopterparentingreferstoastyleofparentswhoareoverfocusedontheirchildren. 1Forexampleitcanincreasefeelingsofloveandacceptance.Howeverhelicopterparentingmaybeharmfultochildren'sdevelopmentinthefollowingways. Decreasedconfidenceandselfesteem自尊.Themessagetheparents'overinvolvementsendstokidsismyparentsdon'ttrustmetodothisonmyown.2 Increasedanxiety.AstudyfromtheUniversityofMaryWashingtonhasshownthatoverparentingisassociatedwithhigherlevelsofchildanxietyanddepression. Undevelopedproblemsolvingskills.Ifparentsarealwaystheretocleanupachild'smessorpreventtheprobleminthefirstplacehowdoesthechildeverlearntodealwithlossdisappointmentorfailure?3 Strengthenedsenseofentitlement权利.Childrenwhohavealwayshadtheirsocialacademicandathleticlivesadjustedbytheirparentstobestfittheirneedscanbecomeaccustomedtoalwayshavingtheirwayandthustheydevelopasenseofentitlement. 4Parentswhoalwaystieshoesclearplatesandpacklunchesevenafterchildrenareabletodothetaskspreventtheirchildrenfrommasteringtheselifeskillsthemselves. Soparentsshouldletchildrenstruggleallowthemtobedisappointedandwhenfailureoccurshelpthemtoworkthroughit.5Remember:takingonestepbackfromsolvingchildren'sproblemswillhelpbuildtheindependentandselfconfidentkids. A.Weakenedlifeskills. B.Damagedlifeexperiences. C.Andthisdistrustleadstoalackofconfidence. D.Helicopterparentinghasmanybenefitsforchildren. E.Parentsshouldalsoletchildrendotaskstheyarephysicallyandmentallyabletodo. F.Makingyour3yearold'sbedsoundsreasonablewhilemakingyour13yearold'sbeddoesn't. G.Studiesfoundhelicopterparentingcanmakechildrenfeellessableindealingwiththestressesoflifeontheirown.
假定英语课上老师要求同桌之间交换修改作文请你修改你同桌写的以下作文.文中共有10处语言错误每句中最多有两处.每处错误仅涉及一个单词的增加删除或修改. 增加:在缺词处加一个漏字符号Ʌ并在其下面写出该加的词. 刪除:把多余的词用斜线\划掉. 修改:在错的词下划一横线并在该词下面写出修改后的词. 注意:1.每处错误及其修改均仅限一词 2.只允许修改10处多者从第11处起不计分 Beingaseniorstudent.IlikeEnglishmorethananyothersubject.BesideshavingEnglishlessonsatschoolIgototheEnglishCornerintheparkwhereisnearmyhomeatSaturdaymornings.ItsetuptwoyearsagowiththepurposeofhelpingstudentsmakeaprogressinEnglish.Manyhighschoolstudentsregulargatherhere.Sometimes.somecollegestudentsorevenforeignfriendsarepresentattheEnglishCorner.TherewepractisespokenEnglishtalkedaboutwhatweareinterestedinintroducingourexperienceinlearningEnglishandsoon.IhadgreatlyimprovedinEnglishsinceIattendedthemforthefirsttime.
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