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已知函数f(x)=(x∈R),若等比数列{an}满足a1a2019=1,则f(a1)+f(a2)+f(a3)+……+f(a2019)=( )
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高三下学期数学《》真题及答案
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已知abc成等比数列则二次函数fx=ax2+bx+c的图象与x轴交点个数是
0
1
2
0或1
定义域为集合{12312}上的函数fx满足①f1=1②|fx+1-fx|=1x=1211③f1f6
定义在-∞0∪0+∞上的函数fx如果对于任意给定的等比数列{an}{fan}仍是等比数列则称fx为保
①②
③④
①③
②④
已知函数fx=log2x等比数列{an}的首项a1>0公比q=2若fa2a4a6a8a10=25则f
1006×2010
1006×2011
1005×2011
1006×2012
若abc成等比数列则函数fx=ax2+bx+c的图象与x轴交点的个数为.
定义在-∞0∪0+∞上的函数fx如果对于任意给定的等比数列{an}{fan}仍是等比数列则称fx为保
各项均为正数的等比数列{an}满足a1a7=4a6=8若函数fx=a1x+a2x2+a3x3++a1
各项均为正数的等比数列{an}满足a1a7=4a6=8若函数的导数为f′x则=.
.定义在-∞0∪0+∞上的函数fx如果对于任意给定的等比数列{an}{fan}仍是等比数列则称fx为
①②
③④
①③
②④
不相等的三个正数abc成等差数列并且x是ab的等比中项y是bc的等比中项则x2b2y2三数
成等比数列而非等差数列
成等差数列而非等比数列
既成等差数列又成等比数列
既非等差数列又非等比数列
.已知函数fx是定义在R.上的不恒为零的函数且对于任意实数xy满足f2=2fxy=xfy+yfx考查
若abc成等比数列则函数fx=ax2+bx+c的图象与x轴交点的个数是
0
1
2
不确定
定义在-∞0∪0+∞上的函数fx如果对于任意给定的等比数列{an}{fan}仍是等比数列则称fx为保
①②
③④
①③
②④
已知函数fx=x≠-1x∈R数列{an}满足a1=aa≠-1a∈Ran+1=fann∈N*.1若数列
已知abc成等比数列则二次函数fx=ax2+bx+c的图象与x轴交点个数是
0
1
2
0或1
互不相等的三个正数x1x2x3成等比数列且点P1logax1logby1P2logax2logby2
等差数列,但不成等比数列
等比数列而非等差数列
等比数列,也可能成等差数列
既不是等比数列,又不是等差数列
等比数列{an}中a1=1a8=4函数fx=xx﹣a1x﹣a2x﹣a3x﹣an若y=fx的导函数为y
1
2
8
2
12
2
15
已知数列{an}满足:a1=1a2=aa>0.数列{bn}满足bn=anan+1n∈N*.1若{an
已知x>0y>0xaby成等差数列xcdy成等比数列则的最小值是.
0
1
2
4
定义在-∞0∪0+∞上的函数fx如果对于任意给定的等比数列{an}{fan}仍是等比数列则称fx为保
①②
③④
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MTLEDANONICECENTER*900CEDARBOULEVARD* PITTSBURGHPA15228 412561﹣4363www.mtlebanon.org WHOSkatersofallagesandabilities.Mustbe3yearsofageandpottytrained. AnyPreschoolKindergartenagechildwhohasnevertakenlessonsattheMr.LebanonIceCenterneedstobeevaluated. TheOn﹣lineregistrationfeaturedoesnotapplytoevaluationregistration. Evaluationdatesandtimesarelistedbelow. EVALUATIONSEvaluationshelptodeterminebothreadinessandclassplacement.Uponcompletionoftheevaluationitisrecommendedthatyouregisterforclasseswithanassociatelocatedintheicecenterbooth.AvarietyofdaysandtimesfortheevaluationsarealsolistedonlineandattheIceCenter. Evaluationregistrationmaybedoneinpersonorbyphoneat412﹣561﹣4363. AdditionalevaluationdatesmaybeofferedforsessionⅡ. REFUNDPOLICYRefundrequestsmustbemadeaminimumof7dayspriortoevent.Seewww.mtlebanon.orgfordetails. REGISTRATION Inperson﹣StopbytheMt.LebanonRecreationCentergroundfloorMondaythroughSaturday900a.m.900p.m.orSunday900a.m.530p.m. ByPhone﹣CalltheIceCenterat412561﹣4363toscheduleyourskatingevaluationappointment MakecheckspayabletoMt.LebanonPAvisaMasterCard&DebitCardsaccepted QLESTIONSPleasecalltheMt.LebanonIceCenterstaffat412561﹣4363 LeboALERT﹣AFREEnotificationservicephonetexte﹣mail.Intheeventofanemergencyandtoprovideyouwithupdatesaboutcancellationsandrecreationdepartmentprogramsandevents.Pleasevisitwww.mtlebanonorgandsignupforLeboALERT.AllrecreationparticipantsshouldsignupandatminimumselecttheCancellationscategory. 1What'sthepassagemanlyabout? A.Tointroduceaskatingprogram. B.Toadvertiseaskatingcenter. C.Toserveasaskatingassessmentschedule. D.Toissueafreeskatingnotification. 2Mary'smotherwantstoregisterstheevaluationforherdaughter.Whichtimeasfollowsissuitableforhertogotothecenter? A.Monday830a.m. B.Wednesday2p.m. C.Friday930p.m. D.Sunday600p.m. 3Whichofthefollowingistrueaccordingtothepassage? A.Theevaluationisintendedforallpreschoolandkindergartenchildren. B.Refundrequestscanbeacceptedwithin7daysaftertheregistration. C.ParticipantswhosignupforLeboAlertcanreceivefreenotificationabouttheevent. D.Evaluationregistrationcanbedoneinpersonbyphoneoron﹣line
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ChinesePresidentXiJinpinghaspraisedagroupofmiddleschoolstudentsfortheireffortsinsatellitedesign.Hesaidhewaspleasedwiththeircuriosityandbraveryin1scienceexploration. ThepresidentalsowishedtheteachersandstudentsinBayiSchool2happynewyear. Ximadethepraiseinaletter3writetothestudentsinBeijing'sBayiSchoolonSaturday. Asmallsatellitedesignedanddevelopedbythem4sendintospacelastWednesdayatTaiyuanSatelliteLaunchCenter5itwasdesignedtooperateinorbitfor180days. ThreemonthsagoXireturnedto6hehighschooltovisitalaboratoryandtalktoteachersandstudents7weredesigningthesmallsatellite.Thepresidentsaidhewas8extremegladtoknowthatthesatellitedesignedbythestudentswouldbelaunchedandcalledonthemtobecome9buildofthecountry.Xiwarmlyencouragedthestudents10studyscienceandcontributetothedevelopmentofChina.Hehopedthatthestudentswouldkeephungryforknowledgeanddeveloptheirnationalspirit.
执行如图所示的程序框图如果输入的x∈[02]那么输出的y值不可能为
IntheshorttimeSteveandZachhadbeeninsidetheirtentpackingtheirtoolswind-blownflamehadskippedfromthetopofonetreetoanother.Thelongdrysummerhadturnedtheforestintoatinderbox. Let'sgo!Wecanmakeitbacktotheriverwecrossedtoday!StevekeptBradyontheleadandtheirheadsdownagainstthefire-wind.ButBradybarkedasharpwarning.Aheadofthemlayathickcurtainofsmokeacrossthetrack.Theywouldnevermakeitthroughthat.ThedogwaspullingathisleadtryingtodrawthemawayfromthesmokeandyetStevewasuneasy.Itseemedtohimthattheyweremovingawayfromtheriver. SuddenlyZachcried.Zach!Steveshouted.AreyouOK?Whereareyou?ThenBradypulledStevedownasharpslope坡.AtitsbaseZachwasrubbinghisankle. AsStevehelpedhisfriendtohisfeetBradyliftedhisheadandsnuffed嗅thesmoke-ladenwind.Nextmomentthedogboundedawayanddisappeared.Theboysshoutedforhimbuthedidn'tcomeback.Stevecouldn'tblameBradyforpanicking.Hehimselfwantedtoruneventhoughhedidn'thaveacluewhichway. SteveandZachhadn'tgonefarwhentherewasafamiliarbarkandBradycameboundingstoppeddirectlyinfrontofSteveandhithimwithhisheadpushinghimbacktowardtheslopethey'djustclimbed.ButStevedidn'tgetit.ThenBradygrabbedtheboy'sjeansandstartedpulling.ThemessagewasclearbutStevehesitated.OfcourseherememberedBradysavinghisuncle'slifewhenthedogwasmuchyounger.Washestillsharpenoughtogetthemthroughthis? Nearbyapinewentupinawhooshofsmoke.Bradypulledagainurgently.OKbigguyStevegritted咬紧牙关.Bradyledthembackdowntheslopeandintothetrees.Notfarfromthemfirewastouchingunderbrush.Severaltimesthebigdogstopped.Oftenhechangeddirections.StevewassotiredthathejustwantedtorestbutBradywouldn'thaveit.Thedogbulliedbothboystogoon.Howlongthey'dwalkedStevehadnoidea.Hewasalmostnumbwhenheheardit-thewonderfulsoundofrushingwater! 1WhathappenedtoSteveandZachatfirst? A.Theygotinjured. B.Theylosttheirdog. C.Theyweretrapped. D.Theybecameseparated. 2Bradyranawayto. A.seekhelp B.findawayout C.rescueZach D.escapeforlife 3HowdidStevefeelafterBradypulledhisjeans? A.Uneasy. B.Impatient. C.Numb. D.Uncertain. 4Thepassagebasicallydescribes. A.anadventure B.anexploration C.anescapegame D.atrainingprogram
假设你是红星中学学生李华.你的英国笔友Jim在给你的邮件中提到他想了解北京近几年发生了怎样的变化.请给他回复邮件内容包括 1.变化 2.原因 3.感受. 注意1.词数不少于50 2.开头和结尾已给出不计入总词数. DearJim Yours LiHua
EveryyeararoundValentine'sDaymenbegintoworryaboutwhat1presenttobuyandwomen2fillwithhopeandexpectation.Ortheotherwayaround.InChinamorecouplesgetmarriedonthatveryday3addromancetotheirpromises.Butformanyloveisneitherthematter-of-coursechoice4thepreferredone.Moreyoungworkingurbanresidentsaredelayingorevenchoosingnotto5activeseektheirpartnersdespitethesocialpressurefromtheoldergenerationstodoso. OvertheyearsChina'sdivorceratehasexceeded超过thatofmarriage.AccordingtothestatisticsfromtheMinistryofCivilAffairs10millioncouplesregisteredformarriagein2017fellby7%6comparewiththesameperiodlastyearwhile43.7millioncouplesdivorced5.2%morethanthesameperiodlastyear. Thereisalsoagrowingtrendtowardspeoplemarryinglatersince2013thenumberofcouplesaged25to29hasbeengreaterthan7ofyoungercouples.Inthe8latesurveyonprofessionalattitudestowardsloveandmarriagemorethanhalfoftheinvestigatedinYangzhou9second-levelcityontheEastcoastweresatisfied10theirmarriageafter35.
BillDraytonbelieveswe'reinthemiddleofanecessarybutpainfulhistoricaltransition.Formillenniumsmostpeople'sliveshadacertain1.Youwenttoschooltolearnatradeoraskill﹣bakingfarmingoraccounting.Thenyoucouldgointotheworkforceandmakeagoodlivingrepeatingthesameskilloverthecourseofyourcareer. Butthesedaysmachinescandoprettymuchanythingthat's2.Thenewworldrequiresadifferentsortofperson.Draytoncallsthisnewsortofpersonalchangemaker. Changemakersarepeoplewhocanseethepatternsaroundthemidentifytheproblemsinanysituationfigureoutwaystosolvetheproblemsinanysituationfigureoutwaystosolvetheproblemorganizefluidteamsleadcollectiveactionandthen3adaptassituationschange. ForexampleAshokafellowAndrésGallardoisaMexicanwholivedinahighcrimeneighborhood.HecreatedanappcalledHausthatallowspeopleto4withtheirneighbors.Theapphasapanicbuttonthat5everybodyintheneighborhoodwhenacrimeishappening.Itallowsneighborstoorganizechatsharecrimestatisticsandworktogether. ToformandleadthiscommunityofcommunitiesGallardohadtopossesswhatDraytoncallscognitiveempathy﹣basedlivingforthegoodofall.Congnitiveempathyistheabilitytoperceivehowpeoplearefeelingin6circumstances.Forthegoodofallisthecapacitytobuildteams. Itdoesn'tmatterifyouareworkinginthecafeteriaortheinspectionlineofaplantcompanieswillnowonlyhirepeoplewhocan7problemsandorganizeresponses. Millionsofpeoplealreadylivewiththemind﹣set.Butalotofpeoplestillinhabittheworldoffollowingrulesandrepetitiveskills.TheyhearsocietytellingthemWedon'tneedyou.Wedon'tneedyourkidseither.Ofcoursethosepeoplegointoreactionarymodeandstrikeback. Thecentral8ofourtimeDraytonsaysistomakeeveryoneachangemaker.Inanearliererahesayssocietyrealizeditneededuniversal9.Todayschoolshavetodevelopthecurriculumsandassessmentstomakethechangemakingmentalityuniversal.Theyhavetounderstandthisistheircriteriaforsuccess. Ashokahasstudiedsocialmovementstofindouthowthiskindof10shiftcanbepromoted.Itturnsoutthatsuccessfulmovementstakesimilarsteps.
Somebestmusicandoperaholidaysfor2019. TanglewoodFestival ThevillagesofLenoxandStockbridgeinwesternMassachusettshavebeenthesummerhomeoftheBostonSymphonyOrchestraformorethan80yearsanditsannualTanglewoodfestivalisEastCoastAmerica'smostdistinguishedmusicevent.AndrisNelsonsBSOmusicdirectorconducts14oftheconcertsandstarperformersincludeEmanuelAxPaulLewisandAnne-SophieMutter.TicketsonsaleFeb10. June15-Aug25tanglewood.org AspenFestival Thisyearisthe70thanniversaryoftheAspenMusicFestivaloneofthelongest-runningandmostprestigiousfestivalsintheUnitedStates.The2019programhasyettobeannouncedbutatypicaleight-weeksummerseasonincludesmorethan400classicalmusicevents-includingconcertsbyfiveorchestrassolo独奏andclassicalmusicperformancesfullystagedoperaproductionsmusiclessonslecturesandchildren'sprogramming.TicketsanddetailsavailableinFebruary. June27-Aug18aspenmusicfestival.com GrandTetonMusicFestival Aspen'sgreatclassicalmusiccompetitorintheRockyMountainsistheGrandTetonwhichhasbeenheldinJacksonHolesince1962andatitsheartisatimberconcerthalltheWalkFestivalHallfamousforitsfriendlyatmosphereandexcellentnaturalsound.Despiteitsrelativelymodestsizethehallattractsthegreats-currentmusicdirectoristheScottishconductorDonaldRunnicles.Theprogramfor2019isyettobeannouncedbutsubscriptionsareonsalefromFeb1singleticketsfromMarch1. July2-Aug17gtmf.org SalzburgFestival TheexcitementisbuildinginSalzburgbothforthissummerandforits100thanniversaryyearin2020.BarthePromsitistheworld'soldestmusicfestivalandthisyearitwillpackinanunbelievable199performancesin43daysat16venues.Thisyear'sthemeis‘Myths'andincludesfirstpublicperformancesofMozart'sIdomeneoandGeorgeEnescu'soperadipe. July20-Aug31salzburgfestival.at 1Whichofthefestivalshastheshortesthistory? A.TanglewoodFestival. B.AspenFestival. C.SalzburgFestival. D.GrandTetonMusicFestival. 2WhatcanwelearnaboutTanglewoodFestival? A.ItisheldfromJune27toAug.18. B.ItsticketscanbeavailablefromMarch1. C.ItisbestknownintheeastcoastofAmerica. D.Itsmoreinformationcanbegotfromgtmf.org. 3WhatisthesimilarityofAspenFestivalandSalzburgFestival? A.TheirticketscanbegotinFebruary. B.Theywillbeheldinthesamemonths. C.Theybothhavemusicandoperaperformances. D.Theiraudiencecanbebothadultsandchildren.
若集合A={x∈Z|x2≤4}集合B={x|-1<x<3}则A∩B=
假如你是李华你的美国朋友Henry非常喜欢中国来信询问你校中国国学经典Chineseclassics的上课情况.请你依照下列要点写一封回信 1.表达问候; 2.介绍国学上课情况; 3.表达祝愿. 注意1.词数100左右; 2.可以适当增加细节以使行文连贯; 3.标题和落款已给出词数不计算在内. DearHenry Sincerelyyours LiHua
Chinahasbecomethefirstcountrytosuccessfullylandaspacecraftonthefarsideofthemoon.TheChang'e-4probe探测器hasalsomadethefirstlunarlandingsince1972.Ithasthetaskofexploringthesideofthemoonthatneverfacestheearth.Thedarksideofthemoonisolderandhasathickersurfacethanthevisibleside.Ittakesthemoonaslongtogoaroundonitsownaxis轴asitdoesforonecompleteorbitaroundtheEarth. TheChineseprobelandedinahugecrater2500kmindiameterand13kmdeep.Thecraterisoneoftheoldestpartsofthemoonandoursolarsystem. Scientistshopetolearnmoreaboutthegeologyofthefarsideofthemoon.Thecrafthastwocamerasonboardwhichwillsendimagesbacktoearth.Itwillalsoattempttosendsignalstodistantregionsofspacesomethingthatcannothappenonearthbecauseoftoomuchradionoise. Chang'e-4alsohasinstrumentsonboardtoexaminemineralsaswellasacontainerwithseedswhichwilltrytocreateaminiature微型的biosphere生物圈. Communicationwiththespacecraftisnoteasy.Imagesandotherdatamustbetransmittedtoaseparatesatellitebecausenodirectcommunicationwiththeearthispossible. ForChinatheChang'e-4missionisanimportantachievementbecausethecountryhassuccessfullydonesomethingnoothernationonearthhas.Itwantstobecomealeadingpowerinspaceexplorationandhasannouncedplanstosendastronautstothemoonandsetupitsownspacestation. 1WheredidtheChang'e4probeland? A.Onthelunarsidefacingtheearth B.Ontheinvisiblesideofthemoon C.Inayoungercrateronthemoon. D.Inapreviousspacestation. 2Whyisthecraftequippedwithacontainer? A.Toseewhatseedscancomeoutonthemoon. B.Tocollectsomeimportantmatteronthemoon. C.Tofindwhethertheseedscangrowonthemoon. D.Tocheckwhethersomemineralsexistonthemoon. 3Whatcanwelearnfromthetext? A.Thedarksideofthemoonisascoldastheotherside. B.Thebrightsideisyoungerandthinnerthantheotherside. C.Otherplacesinspacemayhardlyreceivesignalsfromthecraft. D.Thetwocamerasonthecraftcansendpicturestotheeartheasily. 4AccordingtothetextwhatwillChinadointhefuture? A.Chinawilllandmannedspacecraftonthemoon. B.Chinawillbuiltanotherspacestationonthemoon. C.Chinawilllaunchmorespaceprobestothemoon. D.Chinawillbecomethefirstcountryinexploringspace.
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PeopleYou'veNeverHeardofWhoChangedtheWorld Itisafactthatmostpeoplelivetheirlivesunremarkedbyhistory.Whetherbydesignorbyaccidenttherearesomepioneerswhoseachievementschangedthecourseofhistorybutwhosenamesareunknowntous. JamesHarrison JamesHarrisonhassavedthelivesofovertwomillionpeoplebydonatinghisblood1173timesaGuinnessworldrecord.Hisbloodproducesarareantibody抗体whichcurestheotherwisedeadlyRhesusdiseaseinunbornchildren.Ithasalsobeenusedinthedevelopmentofamedicineanti-DwhichwillcuretheRhesusdiseaseinchildrenforever. LewisLatimer AfterhelpingAlexanderGrahamBellobtainhispatentforthetelephoneLewisLatimerpatentedacarbonfilament碳灯丝whichallowedlightbulbstoburnforhoursbeforeburningoutmuchmoreusefulthanthatinventedbyThomasEdison.Latimerwentontoinventmanyotherusefuldevicesincludingadevicewhichcooledandcleanedpatients'roomsinhospitals. MauriceHilleman Notallachievementsrequirebraveryandself-sacrifice.TakeMauriceHillemanforexample.Hefoundanotherwaytochangetheworld.Hedevelopedthemumpsvaccine疫苗afterhisdaughtergottheillness.Andhedidn'tstopthere.Intotalhehassingle-handedlydevelopedover40vaccinesincludingeightcommonlygiventochildren.Hisworkhassavedmillionsoflivesandpreventedseriousconsequencesduetothediseases. NilsBohlin In1959NilsBohlinpatentedarevolutionarydesignthathassavedmillionsoflives-thethree-pointsafetybelt.Aftertheinitialresistancefromdriverswhohatedbeingtoldwhattodoandevenfortheirowngoodthethree-pointbelthasbecomeastandardfeatureinnewcarsaroundtheworld. 1Whosepatentallowedlightbulbstoburnforhoursbeforeburningout? A.AlexanderGrahamBell. B.LewisLatimer. C.ThomasEdison. D.NilsBohlin. 2What'sthesimilaritybetweenJamesHarrisonandMauriceHilleman? A.Theybothhadspiritsofbraveryandself-sacrifice. B.Theircontributionssavedthelivesofmanychildren. C.Theydevotedthemselvestoworkbecauseoffamilymembers. D.TheybothsetaGuinnessworldrecord. 3Whatwasdrivers'initialattitudetothethree-pointseatbelt? A.Theyrefusedtouseit. B.Theyweresatisfiedwithit. C.Theyweresurprisedatit. D.Theygotexcitedaboutit.
Helicopterparentingdescribesastyleofraisingchildrenwhereparentsareoverprotectiveanddotoomuch.Itdescribesparentswhowatchovertheirkidsathomeandontheplaygroundlikeahelicopter.Todaymoderntechnologyallowsthesehelicopterparentstowatchoverfromevenfaraway.1 JulieLythcottwroteabooktitledBreakFreeoftheOverparentingTrapandPrepareYourKidsforSuccess.Inherbook.shegivesreadersacloserlookatthisparentingstyle.2 JulieLythcottsayssheexperiencedtheeffectsofhelicopterparentingfirsthandwhensheworkedasdeanoffirstyearstudents.3Butmanywereunabletotakecareofthemselves.Heywereturningtoparentsconstantlyforguidanceforproblemsolvingtohavethemmakethechoiceaboutsomething. Sowhatcanparentsdoiftheywanttobreaktheover-parentinghelicoptercycle?4 ◆Stopsayingwewhenyoumeanyoursonoryourdaughter.Alltoooftenaparentwouldsayweareonthetravelsoccerteam.Wellnoyoursonisoryourdaughteris. ◆Stoparguingwithalloftheadultsinourkids?lives.Youneedtoteachyourkidstoadvocateforthemselves. ◆Stopdoingyourkids'homework. ◆5Teachthemtocrossthestreetmakeamealandremembertoputtheirownitemsintheirbackpackswhichbecomesabriefcaseoneday. Whenkidshavealltheskillstotakecareofthemselvestheywillbepreparedforadulthood. A.Fourwaysareofferedtostopwatchingoveryourchildren. B.Shealsoexplainswhyparentsshouldstopit. C.It'sagoodideatoencourageyourkidtodothethingshecanbyhimself. D.Theycangivetheirchildrendirectionsatanymomentfromanywhere. E.Buildyourkids'skills. F.Thefreshmenwereverysmartandaccomplishedonpaper. G.Yourkidiseagerformorefreedombutshouldyougiveittohim?
Areyoutryingtofindwaystobemoreefficientatyourjob?Ifsopleasefollowthesehabitsofnaturallyproductivepeople. Theytakebreaks.1Studiesshowthatprolongedtasksthatrequirehighlevelsoffocusenergyandattentioncancauseyoutobecomelessproductiveandfocusedovertime.Takebriefmentalbreaks.Settingasidealittletimehereandtheretoreleaseyourfocuscansignificantlyhelpmaintainitforlongerperiodsoftime. 2Settledownsupermenandwomen.Whileit'sfinetoprideyourselfonyourabilitiestomultitaskit'sinyourbestinterestandyouremployer'sifyousticktooneto-doatatime.Somewherealongthelinesourculturehasembracedandpromotedthisideathatthemorewecandoatoncethebetter.3Infactthemorewemulti-taskthelessefficientandproductivewebecomeinallthetaskswearetryingtoaccomplish. Theyhaveafullnight'ssleep.Inschoolyoumayhavefoundthattoomanystudentsstayuplatetofinishapaperorstudyforanexambutdespiteyourbesteffortsresearchshowsthisisnotthewaytodobusiness.4Actuallystudieshavelinkedinsufficientsleeptodecreasedlevelsofproductivityunsatisfactoryworkperformanceandpoorersafetyoutcomes. 5Youknowthecountlessbenefitsofexercise.Italsoseriouslyimprovesyourmoodbyreleasingsomethingtorelievestressandincreaseyourbrainsproductivity.Even30-minuteburstsofmoderate-to-highphysicalactivityjustthreetofourtimesadaycangoalongwayinhelpingyouaccomplishyourpersonalandprofessionalgoals. A.Theyvaluefitness. B.PressingpauseIsImportant. C.Theyprefertodomoreeveryday. D.Howeverresearchshowstheopposite. E.Theydon'ttrytodoeverythingatonce. F.Enoughsleepmakesgreatcontributiontoefficientwork. G.Poorsleeporlackofsleepcarriessomeprettynegativerewards.
已知点P是边长为2的正方形ABCD所在平面内一点若则的最大值是
OKsoit'snotarealwar-buttheU.S.andChinaareatthebeginningofatradewarthankstoPresidentTrump'spolicy.TheChinesegovernmentraised34billiondollarsinnewdutiesongoodsexportedfromtheU.S.lastweekinreplytoPresidentTrump'sunwisetariffs关税of34billiondollarsonChinesegoods. Farmandseafood-producingstatesaregoingtobehithardestbyChina'snewtariffsonU.S.goods.StateswherecarsaremadeandshippedtoChinaareonthehookaswell. Intermsofvaluesome38percentofproductsonthetarifflistarerelatedtoagricultureincludingsoybeanssorghumtobaccoandmeat.That'snothinglikegoodnewsforfarm-beltstatesprimarilyintheMidwestlikeIowa. AwiderangeofseafoodisonChina'starifflist.ThatcouldhurtfisheryworkersinAlaskaandlobsterharvestersinMaine.AlaskaforexampleexportednearlyIbilliondollarsworthofseafoodtoChina.ChinaisamajormarketforAlaskaseafoodsaidAlexaTonkovichExecutiveDirectoroftheAlaskaSeafoodMarketingInstitute.Theseafoodindustrydirectlyemploysnearly60000workersinAlaskaeachyearanddirectlyemploysmoreworkersthananyotherprivateindustry. AndautomakingstatesparticularlyintheSoutharealsoatrisk.Some24percentofproductsonthelist-intermsofvalue-arecarstrucksandothervehicles.Michiganaloneexported$1.7billionworthofmotorvehiclesandvehiclepartstoChinain2017.OtherstatesbeingaffectedincludeSouthCarolinawhereBMWmakesSUVsforboththeU.S.andexportersandAlabamahometoMercedes-BenzToyotaHondaandHyundaifactories. Thisroundoftariffssparessomeindustrieslikecommercialaircraft.WashingtonStatewhichishometoBoeingcouldbreatheasighofrelief.Italsoforthemomentskipstariffsonchemicalproducts. AlexaTonkovichhaswarnedtheU.S.governmentthatthetradewarcouldriskemploymentreduce industryprofitsandcausethehigherpricesforconsumersintheU.S.! 1Whatdoestheunderlinedphraseonthehookmean? A.Delightedintheirluck. B.Lostindeepthought. C.Caughtinadifficultsituation. D.Stuckintrafficjams. 2Whichstatewillbehurttheleastonthisroundoftariffs? A.Washington. B.Iowa. C.Maine. D.Michigan. 3WhatisAlexaTonkovich'sattitudetowardsthetradewar? A.Approving. B.Sympathetic. C.Objective. D.Opposed. 4Whichofthefollowingshowsthedevelopmentofideasinthetext? A.I-P1-Spl-Sp2-P2-Sp-C B.I-PI-Sp-P2-Spl-Sp2-C C.I-P1-P2-Spl-Sp2-Sp3-C D.I-PI-Spl-Sp2-Sp3-P2-C IintroductionPPointSpSub-point次要点CConclusion
假定你是李华你的英国朋友Peter听说现在在中国人工智能已经进入人们的日常生活包括旅游业.他来信询问你十一假期是否有这方面的体验请给他回信内容包括 1.门票无现金手机支付 2.脸部识别人景区 3.邀请他来体验. 注意 1.词数100左右 2.可以适当增加细节以使行文连贯 3.开头和结尾已给出不计入总词数. 参考词汇人工智能artificialintelligence脸部识别facerecognition DearPeter. I'mhappytohearfromyou. Yourstruly LiHua
把5个人安排在周一至周五值班要求每人值班一天每天安排一人甲乙安排在不相邻的两天乙丙安排在相邻的两天则不同的安排方法有种.
某三棱锥的三视图如图所示则该三棱锥的体积为
已知椭圆的左右顶点分别为AB长轴长为4离心率为.过右焦点F的直线l交椭圆E于CD两点均不与AB重合记直线ACBD的斜率分别为k1k2. Ⅰ求椭圆E的方程 Ⅱ是否存在常数λ当直线l变动时总有k1=λk2成立若存在求出λ的值若不存在说明理由.
已知等差数列{an}的前n项和为Sn能够说明“若数列{an}是递减数列则数列{Sn}是递减数列”是假命题的数列{an}的一个通项公式为.
在△ABC中角ABC的对边分别为abc且. Ⅰ求B的值 Ⅱ求sinA+sinC的最大值.
DuringmysecondyearinhighschoolIgotsickandmissedafewdays.WhenI1Iwasgreetedwithtwoessaysduethreedaysofmathandhistoryhomeworkplusseveraltests.2IwenthomefromschoolthatdayexhaustedIhadtostayupreallylatetofinishthemall. ThenextdayatschoolIgotarudeawakeningI'dtotallyforgottentoprepareforthe3onRomeoandJulietwhichI'dtake4mylunchhour!WorsestillIhad5thein-classdiscussionandallthenotes.WhenlunchcameIwenttotheEnglishroomtofacemycertaindoom厄运.AllIcoulddowastryto6onthequestionsIdidn'tknow. AsitturnedoutIdidn'tknowthemajorityofthequestions.Iwasjustabouttogive7whenmypencilaccidentallyfellandbroke.StandingbytheblackboardsharpeningmypencilI8downandthereinfullviewlaytheanswersheetforthetest!Whatgoodfortune!Icankissgood-byetoallmy9offailingthetest!Myheartstartedbeatingandmybrain10Yes!Readovertheanswers-quickly!ThiswasquicklyfollowedbyanothervoiceNo!You'llgetcaught!MymindturningbackandforthYes!No!Yes!No!…Thiswentonfortenofthe11secondsinmyentirelife. FinallyIdecidedtofinishthetestonmyownwithout12!Iwassatisfiedwithmydecisionbutpretty13Ihadfailedthetest. ThenextdaywhenIwalkedintotheEnglishroommygreatjoyofhavingbeenan14soulchangedintoawaveofdoomasIsawmytestpaperlyingfacedownonmydesk.Iknewwhatawaitedme.IstaredatitafewsecondsbeforeIgotupthe15toturnitover. Youcanonlyimaginemy16whenIlearnedthatIhadpassedthetest!Ihaveneverinmywholelifebeensohappytoseemy17aC-. Mymomsaysthevictoriesthat18themostcouragearewonwithin.NowIknow19whatshemeans.Nownotonlycanmyconscience良心resteasybutIdon'thavetoworryaboutgettingcaughtandmeetingasad20likeRomeoandJuliet. 1A.arrived B.returned C.appeared D.finished 2A.If B.Because C.Until D.Although 3A.lecture B.essay C.play D.test 4A.by B.upon C.over D.toward 5A.missed B.carried C.lost D.dropped 6A.depend B.agree C.guess D.improve 7A.in B.off C.out D.away 8A.wrote B.settled C.calmed D.looked 9A.boredom B.worries C.loneliness D.tiredness 10A.whispered B.warned C.persuaded D.chanted 11A.coldest B.saddest C.longest D.fastest 12A.suffering B.checking C.cheating D.thinking 13A.certain B.regretful C.annoyed D.relieved 14A.open B.honest C.optimistic D.energetic 15A.wisdom B.encouragement C.intention D.nerve 16A.anxiety B.shock C.fear D.appreciation 17A.paper B.credit C.rate D.grade 18A.take B.put C.find D.gain 19A.gradually B.exactly C.willingly D.seemingly 20A.film B.fact C.ending D.love
DirectionsReadthefollowingpassage.Summarizethemainideaandthemainpointsofthepassageinnomorethan60words.Useyourownwordsasfaraspossible.Wherearethebees?Beesareessentialtotheproductionoffoodweeat.Beesmakehoneybuttheyalsopollinatelargeareasofcropssuchasstrawberriesapplesandonions.Aboutathirdofthefoodweeatisaresultofpollinationofthebees.Unfortunatelybeeshavebeendisappearingatanalarmingrate.In2006beekeepersstartedreportingaboutsomethingcalledColonyCollapseDisasterCCD.ThemainsignofCCDisthelossofadulthoneybeesfromahive.InOctoberof2006somebeekeepersreportedthattheyhadlostbetween30and90percentoftheirhives.Thereweremanytheoriesforthedisappearanceofthebees.Butthemostconvincingonehastodowithpesticidesandlifestylesofbeestoday.Nowadaysbeekeepergetmostoftheirincomenotfromproducinghoneybutfromrentingbeestopollinateplants.Thismeansthatthelifeofthetypicalbeenowconsistsoftravellingallaroundthecountrytopollinatecropsastheseasonschange.Thatmeansalotoftravelingontruckswhichisverystressfultobees.Itisnotunusualforupto30%ofthehivetodieduringtransportduetostress.Inadditionbeesthatspendmostoftheirtimelockedupontrucksarenotexposedtowhattheyusuallyliveon.Insteadtheyliveonasweetliquidfromcornusuallypollutedwithpesticides.Theexactreasonforthedisappearanceofbeesisnotsurebutlosingbeesisverycostlytotheeconomy.Thebeepollinationservicesareworthover﹩8billionayear.Withnobeespollinationwillhavetobedonebyhandwhichwouldhaveeffectsonthequalityoffoodandincreasedfoodpriced.Wehearalotaboutbigenvironmentaldisastersalmosteveryday.Butoneofthebiggestmayjustbethelessofthattinyflyinginsect.
双曲线的离心率为.
在梯形ABCD中AB∥CDAB=2AD=2CD=4P为AB的中点线段AC与DP交于O点如图1.将△ACD沿AC折起到△ACD'的位置使得二面角B-AC-D'为直二面角如图2. Ⅰ求证BC∥平面POD' Ⅱ求二面角A-BC-D'的大小 Ⅲ线段PD'上是否存在点Q使得CQ与平面BCD'所成角的正弦值为若存在求出的值若不存在请说明理由.
设i是虚数单位若z=则复数z的虚部是
LastfallIhappenedtooverhearastudenttellingtheothershehaddecidednottosignupforanintroductoryphilosophycourse.Thedemandsofhismajorhesaidseriouslymeantheneededtotakepracticalcoursesandenlightenmentwouldsimplyhavetowait.Fornowemployabilitywasthemostimportant. Thestudents'conversationfitsintoalargeralarmingnarrativeabouttheroleofthehumanitiesinhighereducation.InatimeofdizzyingtechnologicalachievementandofrapidscientificinnovationscepticsofthehumanitiesmayquestiontheusefulnessofstudyingAristotletheItalianRenaissanceorChinesefiction. ActuallyIregretnotinterruptingthatstudenttoarguefortakingthatintroductoryphilosophycourse.IwouldhavestartedbyremindinghimthatformuchofAmerica'shistorycollegegraduateswerenotconsideredtrulyeducatedunlesstheyhadmasteredphilosophyliteraturepoliticaltheoryandhistory.Thekeyroleofhighereducationwastoinvitestudentsintotheconversationsaboutmatterslikewhatitmeanstobealiveandthedefinitionofjustice.Fosteringengagementwiththesesubjectsisstillanessentialpartoftheuniversity'sfunctioninsociety. Iwouldhavealsomentionedtothestudentthathewasmisinformedaboutthejobmarket.Itistruethatmanyemployersarelookingforgraduateswithspecializedtechnicalskillsbuttheyalsolookforothercapabilities.Astheworldistransformedbyartificialintelligencemachinelearningandautomationtheuniquehumanqualitiesofcreativityimaginationandmoralreasoningwillbetheultimatecoinoftherealm.Alltheseskillsaredevelopedinhumanitiescourses. FurtherIwouldhavearguedthatwhileadegreeanchoredinthesciencesisanimportantpreconditionformanyjobsitisnottheonlyroute.LooknofurtherthanthefoundersofcompaniessuchasLinkedInSlackandFlickrwhoareamongthemanytechbusinesspersonswithdegreesinthehumanitiesandwhocreditthattrainingfortheirsuccess. Contrarytothewidelyheldbeliefthathumanitiesmajorshaveahardtimegettingjobsrecentstudiesshowthatthosewithhumanitiesdegreesaresuccessfulintheworkplaceexperiencinglowratesofunemploymentandreportinghighlevelsofjobsatisfaction.Theratiobetweenaveragemedian中位数incomesforhumanitiesdegreeholdersandthosewithbusinessengineeringandhealthandmedicalsciencesdegreeshasbeenshowntonarrowoverthecourseofacareer. Thecaseforthehumanitiescanalsobeunderstoodinlesstransactionaltermsandmoreasafoundationalpreparationforalifewelllived.Ahumanitieseducationplaysavitalroleinencouragingcitizenstoleadanexaminedlife.Itfosterscriticalthinkingself-reflectionempathyandtolerancetheusefulnessofwhichonlybecomesmoreapparentasonenavigateslife'schallenges. ByallmeansstudentsshouldtakecoursestheythinkpracticalandfollowtheirinterestsbutiftheyalsomakeapointofstudyingtheliteratureoftheRenaissanceorresearchingintomodernpoetryoreventakingintroductoryphilosophywewillallbenefit. 1Whatdothestudents'conversationshow? A.Studentsfeelemploymentdifficult. B.Studentsthinkphilosophylessimportant. C.Studentsfindscientificinnovationamazing. D.Studentsconsideruniversitycoursesunsatisfying. 2WhatdoestheunderlinedpartinParagraph4probablymean? A.Highlyvalued. B.Equallyapplied. C.Strictlyassessed. D.Greatlyimproved. 3Theauthormayagreethathumanities. A.discoverstudents'artisticability B.preparestudentsforgraduation C.raiseawarenessofsocialstatus D.providegreatinsightsintolife 4Whichofthefollowingshowsthedevelopmentofideasinthepassage? A. B. C. D. IIntroductionPPointSpSub-point次要点CConclusion
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