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已知向量,满足,则向量的夹角的大小为 .
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高三下学期数学《》真题及答案
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已知向量a和向量b的夹角为135°|a|=2|b|=3则向量a和向量b的数量积a·b=_______
已知非零向量abc满足a+b+c=0向量ab的夹角为120°且|b|=2|a|求向量a与c的夹角
已知向量a与向量b的夹角为30°|a|=2|b|=那么向量a和向量b的数量积a·b=.
已知非零向量abc满足a+b+c=0向量ab的夹角为120°且|b|=2|a|则向量a与c的夹角为_
已知向量ab满足|a|=1|b|=2a与b的夹角为60°则|a-b|=________.
已知向量m与n满足且则向量m与n的夹角为.
已知向量ab满足|a|=1|b|=3ab之间的夹角为60°那么a·a+b=.
已知向量ab满足|a|=3|b|=2a与b的夹角为60°则a·b=________若a-mb⊥a则实
已知向量ab满足|a|=2|b|=1a与b的夹角为60°则|a-2b|等于.
已知向量ab满足a+2b·a-b=-6且|a|=1|b|=2则a与b的夹角为____________
已知向量ab的夹角为60°且|a|=2|b|=1则向量a与a+2b的夹角等于________.
已知向量ab满足|a|=1|b|=4且a·b=2则a与b的夹角为________.
已知ab是非零向量且满足a-2b⊥ab-2a⊥b则a与b的夹角是
已知向量ab满足a+2b·a-b=-6且|a|=1|b|=2则a与b的夹角为________.
已知向量a和向量b的夹角为30°|a|=2|b|=3则向量a和向量b的数量积ab=_______
已知向量a和向量b的夹角为30°|a|=2|b|=3则向量a和向量b的数量积a·b=.
已知非零向量ab满足向量a+b与向量a-b的夹角为那么下列结论中一定成立的是
|a|=|b|
a=b
a⊥b
a∥b
已知向量ab的夹角为60°且|a|=2|b|=1则向量a与向量a+2b的夹角等于
150°
90°
60°
30°
已知向量则a与b夹角的大小为_________.
已知单位向量αβ满足α+2β2α-β=1则α与β夹角的余弦值为_________.
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已知向量的夹角为60°||=2||=4则-=
Childrenwhohavedevelopedleadershipskillsaresuretohaveabrightfuture.1Notonlywilltheygainmoreself-esteemandinteractmoreeasilywiththeirpeerstheycanalsomakeanimpactontheircommunity.Thesequalitieswillcontinuetodevelopaschildrengrowup.Herearesimpletechniquestodevelopchildren'sleadershipqualities. Discusspeerpressure.Childrenareoftenexposedtopeerpressureandworryabouthowothersviewthem2Leadershiprequiresbeingsociallyinvolvedbutstillhonoringpersonalmoralsandstandards.Discusshypothetical假设的peerpressuresituationsandaskkidstoconsiderhowthey'dbehaveindifferentsituations 3Whenthey'reabletoclearlyshowtheirthoughtstheyfeelmoreself-confidenttodealwithcomplexproblemsYoucanhelpbyencouragingchildrentospeakoutandbylisteningseriouslytotheirthoughts.Althoughmanychildrengothroughrebelliousstagesdon'tenforcesilence.Insteadsuggestself-expression. Teachbyexample.4Eveniftheydon'texpressitaloudchildrenmayseeyouasarolemodel.Modelleadershipbehaviorbyhelpingothersvolunteeringinleadershippositionsandtakingactionineverydaylife. Developchildren'sindividualtalentsandencourageparticipation.Everychildhaspotentialforleadershipskillsbutnoteverychilddevelopsskillsinthesameway.5Achildmightbeatalentedathleteorskilledatpaintinganddrawing.Findwaysforkidstodeveloptheseskillsinagroupsettingwhichpromotesteamworkandsocialskills. A.Encouragechildrentoexpressthemselves. B.Payattentiontospecificinterestsandabilities. C.Findvolunteerandcommunityserviceopportunities. D.Childrenstartbenefitingfromleadershipskillsatanyage E.Childrenwithself-awarenesshaveagreaterabilitytolead. F.Childrenobservetheadultsintheirlivesandvaluewhattheysee. G.Talkwithyourchildrenabouttheimportanceofavoidingpeerpressure.
ThehistoryofAustralianRulesFootball AustralianRulesFootballiscalledbymanynicknames.Loversofthegamejustcallitfootballorfooty.WhencontrastedwithotherformsoffootballitiscalledAussieRulesorAFL.AFLstandsforAustralianFootballLeaguewhichisthemostprestigiousleagueinAustralia. AustraliaRulesFootballwascreatedbyTomWillsin1858.Hewantedtocreateasportthatwouldkeepcricketplayersfitthroughthewinter.Hebeganbywritingaletterthatexplainedhispurposetoasportsmagazine.Italsocalledforthecreationofafootballclub.In1858WillsandothersplayedanexperimentalmatchthatwasthefirstgameofAustralianfootball.Butfewdetailsaboutthismatchhavesurvived. OnAugust71858twoimportanteventsforthegameoccurred.TheMelbourneFootballClubwasfounded.Itwasoneoftheworld'sfirstfootballclubsinanycode.AlsoafamousmatchbetweenMelbourneGrammarSchoolandScotchCollegewasplayed.Itwasumpired仲裁byTomWills.AseconddayofplaytookplaceonAugust21andthentherewasathirdandfinaldayonSeptember4.Thetwoschoolshavecompetedeveryyearsince. Thegameisplayedbetweentwoteamsof18playersonanovalthatcanalsobeusedforcricket.Theseplayingfieldscanbeupto185mlong.Thisisalmostfourtimesthesizeoffieldsusedinotherformsoffootball. Apointcalledabehindisscoredwhentheballgoesacrossthelineandbetweenagoalpostandabehindpost.Abehindpointisalsoscorediftheballistouchedbyanybodypartofeitherteam'smemberasitpassesbetweenthegoalposts.Agoalisworthsixpointsandabehindisworthonepoint. 1AccordingtoparagraphlallofthefollowingarenicknamesforAustralianRulesFootballEXCEPT. A.soccer B.footy C.AussieRules D.AFL 2AccordingtothepassageTomWillscreatedAustralianRulesFootballbecause. A.helikedcontributingtosportsmagazines B.hewantedtoumpireagamebetweenMelbourneGrammarandScotchCollege C.hewantedcricketplayerstokeephealthyduringthewinter D.hewantedtojointhemostprestigiousleagueinAustralia 3Theunderlinedphraseinanycodeinparagraph3isclosestinmeaningto. A.ofanyname B.inanyorder C.inanycountry D.ofanystyle
InhisbookIntentionalLivingauthorJohnMaxwellsharesthatbackin1976hereceivedagiftfromoneofhis1assist.Asheunwrappedthegifthesawthatitwasabook2nameTheGreatestStoryEverTold.Hecouldn'twait3readit. Butwhenheopenedthebookhewas4astonishtoseethatthepageswereblank.Insidethebookwas5notethatsaidJohnyourlifeisbeforeyou.Fillthesepageswithkindactsandgoodthoughtsofyourheart.Writeagreatstoryaboutyourlife.Theintentionofwritingthestoryofhislifeexcitedhim.Thenhe6begintowritehisbook. Everydayweliveoutourstorythroughourwordsactionsanddecisions.Butwemustremembertolivewithintentiontofocusonwhat7mattermostinlifeandtoregainthatfocuswhenwegetchanged.Withoutintentionwecanbecomeunfocusedinthings8needn'taddtoalifeofsignificanceanddifferenceinourworld. Lifeisn'tperfectandit'salwayshard9weneedremindersinourlifefromafriendauthorbloggerpastororourinnerspirittore-focususonthethingsthatmatterandmakeuslive10positive.
It'scommonknowledgethatsomecountrieshavehigherlifeexpectanciesthanothersbutthecityyouliveincanalsoaffectyourhealth. Somecitiesarehardontheirresidents.InplaceswithpoorcityplanningforexampleLagoswhichwascalledoutrecentlybytheEconomistIntelligenceUnitpublicspacesarefewmakingoutdooractivitieshard.Lackofinfrastructure基础建设blocksthestreetswithcarsandtheairwithpollutantsandresidentsworklonghoursforlittlemoney. ThesearejustsomeofthefactorsaddedupbySpotahomearentalagency.They'veanalyzeddatafromarangeofsourcesincludingtheWorldHealthOrganizationTripAdvisorandtheCIAWorldFactbooktoscoreeachcityonhealthgymavailabilityandqualitylifeexpectancyobesitygreenspaceandotherelementstomakealisttoworkoutwhicharetheworld'shealthiestcities. ThelistiscertainlyEuro-centricandsunshineisseenasapositivefactor.Itdoesgosomewaytowardssuggestingwhichcitiesaregettingitrightinprovidingagoodlifefortheirresidents.ItmaynotbesurprisingtolearnthatmostofthehealthiestcitiesareinnorthernEuropeknownforitspeople-firstapproachtocityplanning.ThecitiesofAustraliaandCanadaalsodowell.HoweverthefirstAmericancityisonlyin34thplace.TheUKdoesn'tfaretoowelleither-itsonlycityinthetop50listisLondonin40th. Whetheryou'replanningawholesomeholidayorsimplywonderingwhatyourcitycandobetterinitsquestforhappycitizensthelistofthe50healthiestcitieswillgiveyoupauseforthoughtaboutthefutureofcityplanning.Herearetheslenderhealthy-eatingclean-airedcitiesthataregettingitright. 1Whatplaysthekeyroleinbuildingahealthycityaccordingtothetext? A.Localculture. B.Cityplanning. C.Economiccondition. D.Geographicalposition. 2Whatdoesparagraph3mainlytalkabout? A.Howthelistofhealthiestcitiescameintobeing. B.WhatSpotahomediscoveredintherecentstudy. C.ThereasonswhySpotahomecarriedoutthestudy. D.Theplaceswherethedataofthestudycamefrom. 3Whatcanwelearnfromthetext? A.CitiesinAmericalackenoughsunshine. B.TheUKrankedhigherthanAmericainthelist. C.AustraliaandCanadahavethebestcityplanning. D.SomepeopleinLagosmayliveapoorlife. 4Whatmaybethebesttitleforthetext? A.Thebestplacestohavearichlife B.Thehappiestlifestyleintheworld C.Thecityfactorsaffectingyourhealth D.Thenicecountriestokeephealthy
Haveyoueverrealizedthatthesmallestcountriesintheworldhavesomuchtooffer?Whetherit'shistoricandculturalheritageorunspoilednaturethesemicrostatesareworthavisit. Grenada Grenadaisasmallcountryintheworld.ItislocatedonislandofCaribbeanwhichisalsoknownasTheIslandofSpiceforseveralspiceslikecinnamongingerandrarenutmeg.Grenadareliesontourism.Itspristinebeacheswarmturquoisewaterandunspoilednaturemakeitawonderfulholidaydestination.Recentlyecotourismhasbeengrowingaswell. SanMarino LocatedwithinItalyandsurroundedbytheApennineMountains.SanMarinoisvisitedbyapproximately2milliontouristsannually.It'sabeautifulcountrywhichalsoclaimstobetheoldestsurvivingstateintheworld!Thereforeitsculturalandhistoricheritageisundoubtedlyfascinating.AlthoughverysmallthemicrostatehasalotofarchitecturalattractionsaswellastheRomagnawhichislovedbyItalianswhoareamongthemainguestshere. Maldives MaldivesislocatedonthebankofIndianOcean.Maldiveshasarangeofdifferenthabitatsincludingdeepseashallowcoastandreefecosystemsfringingmangroveswetlandsanddrylands.VisitorstotheMaldivesdonotneedtoapplyforapre-arrivalvisaregardlessoftheircountryoforiginprovidedtheyhaveavalidpassportproofofonwardtravelandthemoneytobeself-sufficientwhileinthecountry. Andorra It'sapicturesquemicrostatefoundinthePyreneesMountainsborderingSpainandFrance.Over10milliontouristsvisitAndorraeveryyear!Unliketheneighboringcountries'highpricesthecountryhasaduty-freepolicyallowingshopperstoenjoylowercosts.Alsotherearewinterandsummerresortssoyoucanvisitanytime. 1WhomightbeinterestedinGrenada? A.Architects. B.Spicelovers. C.Historians. D.Mountainclimbers. 2Whichofthefollowingisagoodchoiceforpeoplewholikebuildingdesign? A.Maldives. B.SanMarino. C.Andorra. D.Grenada. 3WhatisnotrequiredforatravelertoMaldives? A.Money. B.Apassport. C.Avisa. D.Areturnticket. 4WhatmeasurehasAndorratakentoattracttravelers? A.Offeringlowerprices. B.Adoptingvisa-freepolicy. C.Settingnaturalhabits. D.Developingscenicspot.
ArtificialintelligenceAItechnologymaysoonbeausefultoolfordoctors.Itmayhelpthembetterunderstandandtreatdiseaseslikebreastcancerinwaysthatwereneverbeforepossible. RishiRawatteachesAIattheUniversityofSouthernCalifornia'sUSCClinicalScienceCenterinLosAngeles.HeispartofateamofscientistswhoareresearchinghowAIandmachinelearningcanmoreeasilyrecognizecancerousgrowthsinthebreast.Rawatprovidesinformationaboutcancercellstoacomputer.Hesaysthisdatahelpsthemachinelearn.…Youcanputthedataintocomputersandtheywilllearnthepatternsandthepatternrecognitionisimportanttomakingdecisions. DavidAgusisanotherUSCresearcher.Hesaysmachinesarenotgoingtotaketheplaceofdoctors.Computerswillnottreatpatientsbuttheywillhelpmakecertaindecisionsandlookforthingsthatthehumanbraincan'trecognizebyitself.Onceaconfirmedcancerousgrowthisremoveddoctorsstillhavetotreatthepatienttoreducetheriskofcancerreturning.Theformoftreatmentdependsonthekindofcancer. Currentlyresearcherstakeathinpieceoftissueputitonasmallpieceofglassandaddcolortobetterseethecells.Thatprocesscouldtakedaysorevenlonger.Scientistssayartificialintelligencecandosomethingbetterthanjustcountcells.Throughmachinelearningitcanrecognizecomplexpatternsorstructuresandlearnhowthecellsareorganized. Thehopeisthatmachineswillsoonbeabletomakeaquickidentificationofcancerthatisfreeofhumanmistakes.Allofasuddenwehavethecomputingpowertoreallydoitinrealtime…Wecouldn'thavedonethiswedidn'thavethecomputingpowertodothisseveralyearsagobutnowit'sallchanged.Agusaddsthattheprocesscouldbedoneforalmostnocostinthedevelopingworld.Hesaysthathavingalargeamountofinformationaboutpatientsisimportantforamachinetoeffectivelydoitsjobinmedicine. TheUniversityofSouthernCaliforniaresearchersarenowonlystudyingbreastcancer.Butdoctorspredictartificialintelligencewillonedaymakeadifferenceinallformsofcancer. 1InRishiRawat'sresearch. A.thedataputintocomputerscontributestocancerrecognition B.manycancersarebeingstudiedatthemoment C.machinelearninghasreplaceddoctors'work D.thefocusisonthecureforcancer 2DavidAgus'swordsinParagraph3areusedto. A.providesomeadvicefordoctors B.introducethedevelopmentofcancer C.appealtoscientiststoresearchintocancer D.explainthefunctionofAIintreatingcancer 3Whatcanweinferfromthetext? A.AIcanmakedecisionsfordoctors. B.Developingcountriesmightbelackoffunds. C.AIwillhopefullymakeanaccurateidentificationofcancer. D.Computingpowerhaslonghelpedwiththeidentificationofcancer. 4Whatistheauthor'sattitudetowardsAIusedintreatingcancer? A.Positive. B.Indifferent. C.Doubtful. D.Negative.
如图在四棱锥P-ABCD中BC∥ADAD=2BC点E是棱PD的中点PC与平面ABE交于F点设PF=λFC则λ=
已知集合A={x|≤3}集合B={x|x2≤9}则A∩B=
执行如图程序框图所示的程序若输出的x的值为9则输入的x为
在△ABC中角ABC所对的边分别为abc若2sin2A+csinC-sinA=2sin2B且△ABC的面积S=abc.则角B=.
我市高三年级第二次质量检测的数学成绩X近似服从正态分布N82σ2且P74<X<82=0.42.已知我市某校有800人参加此次考试据此估计该校数学成绩不低于90分的人数为
某地种植常规稻α和杂交稻β常规稻α的亩产稳定为485公斤今年单价为3.70元/公斤估计明年单价不变的可能性为10%变为3.90元/公斤的可能性为70%变为4.00的可能性为20%.统计杂交稻β的亩产数据得到亩产的频率分布直方图如图①.统计近10年杂交稻β的单价单位元/公斤与种植亩数单位万亩的关系得到的10组数据记为xiyii=12..10并得到散点图如图②. 1根据以上数据估计明年常规稻α的单价平均值 2在频率分布直方图中各组的取值按中间值来计算求杂交稻β的亩产平均值以频率作为概率预计将来三年中至少有二年杂交稻β的亩产超过795公斤的概率 3①判断杂交稻β的单价y单位元/公斤与种植亩数x单位万亩是否线性相关若相关试根据以下的参考数据求出y关于x的线性回归方程 ②调查得知明年此地杂交稻β的种植亩数预计为2万亩.若在常规稻α和杂交稻β中选择明年种植哪种水稻收入更高 统计参考数据=1.60=2.82xiyi=-0.52xi2=0.65 附线性回归方程=bx+ab=.
假定你是李华你的朋友Mike要来中国学习想在就读的学校附近租房子.现在你已经为他找好了房子请你给他回一封email向他介绍该房子的情况. 内容包括 1.房子基本情况位置大小设施及租金等 2.房东要求. 注意1.词数100左右 2.可以适当增加细节以使行文连贯. DearMike Yours LiHua
假定你是李华.你的留学生朋友Tom以前成绩很优秀.但由于骄傲和懒惰最近他的成绩一落千丈.就此请你用英语给他写一封电子邮件内容包括 1.进行安慰 2.给出劝告不要骄傲不忘初心 3.具体建议努为复习制定学习计划. 注意 1.总词数100左右 2.可以适当增加细节以使行文连贯.
已知球D的半径为3圆A与圆C为该球的两个小圆MN为圆A与圆C的公共弦MN=2若点B是弦MN的中点则四边形ABCD的面积的最大值为.
ThefirstorganizedsystemforsendingmessagesbeganinEgyptaround1500B.C.ThissystemdevelopedbecausethepharaohsfrequentlyneededtosendmessagesupanddowntheNileRiverinordertokeeptheirempirerunningsmoothly.LaterthePersiansdevelopedamoreefficientsystemforsendingmessagesusingmenandhorses.MessagescarriersrodealongtheroadsystemstretchingfromoneendofthePersianEmpiretotheother.Alongtheseroadsfreshmenandhorseswaitedatspecialstationstotakeandpassalonganymessagesthatneededtobesent.Thestationswhereriderspassedmessagesbackandforthwerebuilt23kilometersapartsothemenandhorseswereabletotravelquicklybetweenthem.TheRomanslatertookuphisideaandimproveditbyusingamoreadvancedandextensiveroadsystem. InChinahoweverKublaiKhanhadbuiltuphisownsystemfordeliveringmessages.ThissystemworkedinthesamebasicwayastheRomansystem.ThedifferencewasthatKublaiKhankept300000horsesalongtheroadsofthisdeliverylines.Therewereover10000stationswhereamessagewouldbepassedfromoneridertoanotherwithafreshhorse.InthiswayKublaiKhancouldreceivemessagesfromanywhereinthecountryinonlyafewdays. Itwasnotuntilthe1500sthatawell-organizedpostalsystemappearedagaininEurope.OnefamilythevonTaxisfamilygainedtherighttodelivermailfortheHolyRomanEmpireandpartsofSpain.ThisfamilycontinuedtocarrymailbothgovernmentandprivatethroughoutEuropeforalmost300years. In1653aFrenchmanRenouarddeVelayerestablishedasystemfordeliveringpostinParis.PostalchargesatthattimewerepaidbytherecipientbutdeVelayer'ssystemwasuniquebyallowingthesendertopre-paythechargesinasimilarwaytothemodernstamp.UnfortunatelydeVelayer'ssystemcametoanendwhenjealouscompetitorsputlivemiceinhisletterboxesruininghisbusiness.Eventuallygovernment-controlledpostalsystemstookoverfromprivatepostalbusinessesandbythe1700sgovernmentownershipofmostpostalsystemsinEuropewasanacceptedfactoflife. Thethingthatalltheseearlysystemshadincommonwasthattheywerequiteexpensiveforpublicuseandwereintendedforusebythegovernmentandthewealthy.Howeverin1840aBritishschoolteachernamedRolandHillsuggestedintroducingpostagestampsandapostalratebasedonweight.ThisresultedinloweringpostalratesencouragingmorepeopletousethesystemtostayintouchwitheachotherHisideahelpedtheBritishpostalsystembegintoearnprofitsasearlyas1850.SoonafterthatmanyothercountriestookupMr.Hill'sidea.Andletterwritingbecameaccessibletoanyonewhocouldwrite.TodaytheRolandHillawardsaregiveneachyeartoencourageandrewardfreshideaswhichhelppromotephilatelystampcollecting. 1Whatisthemaintopicofthepassage? A.Howinternationalletterstravel. B.Asurprisingmethodfordeliveringmail. C.Thehistoryofpostalsystems. D.Changesinthemethodsofcommunication. 2WhichofthefollowingstatementsaboutRenouarddeVelayeristrue? A.Hiswasagovernment-controlledsystem. B.Hiscompetitorsdestroyedhisbusiness. C.Hissystemlastedforhundredsofyears. D.Inhissystemthepersonwhoreceivedtheletterpaidthepostagefees. 3Whichofthesystemsmentionedinthepassagewasmostlikethepostalsystemtoday? A.Egyptian. B.Chinese. C.deVelayer's. D.vonTaxis's. 4WhatwasRolandHill'sgreatestachievement? A.Hemadeletterwritingaccessibletotheaverageperson. B.HemadealotofmoneyfortheBritishpostalsystem. C.Hemadestampcollectingapopularhobby. D.Hewonanawardforletterwriting.
假设你是王平.上周你刚买了一台电视机但你发现电视机有问题请你用英文给商店经理写一封信反馈问题.内容包括 1.电视机的问题所在 2.你希望的解决方法及联系方式. 注意 1.词数80词左右 2.可适当增加细节以使行文连贯 3.信件开头和结束已经给出不计入总字数. DearSirorMadam Iboughta37-inchTVsetfor﹩400inyourstoreon15thofthismonth.AsalesgirlnamedMaryservedmeandrecommendedthisbrand. YoursSincerely WangPing
若二项式x6n的展开式中含有常数项则n的值可以是
Myfatherwasahighlyeducatedintelligentgentleman.Hecoulddebateordiscussfor1onalmostanytopicandholdyourattentionintheprocess.Ithoughttherewas2hewasn'tabletodo. Afewdays3myyoungerbrother's7thbirthdayDadplannedtoputtogetherashinynew4asaspecialbirthdaysurprise.Afternearlyanhourof5theinstructionsDadwasstillunabletoputthenewbiketogether.Laterhefoldedupthepaperofinstructions6histoolboxanddecidedtotakethebikebacktothelocaltoystoreandpayextramoneytohaveit7assembled组装there.Thenan8cametohimashecalledouttoLovettthequietlittlemanwhomowedourgrassland. Lovetthaveyoueverassembledaboy'sbicycle?AsLovettwalkedtowardsthebikeDadhandedhimthepaperofinstructions.Lovetthandedit9tohimsayingNothanks.Ican'tread.Whenyoucan'treadyouhaveto10.Lessthan15minuteslaterthenewbicyclewasfullyassembledwithnospareparts11.DadshookLovett'shandpattedhimonthebackthankedhimandhidthebike. Onthenightaftermybrother12hisslm1ynewgift.Dadannouncedatthefamilydinnertable13hadhappenedseveraldaysearlier.Hetookgreatdelightintellingit14---heuseditasanexampleofthinking. Hedidnot15illiteracy文盲butstronglytaughtustouseour16.Thejokewasonmyfather17hewasabletotumitintoalearningtoolandIlikedhimeven18aftertheincident.IalsogainedarespectforLovett.Tomehehadalwaysbeentheoldyardmanwhodidn'tsaymuchbutafterthatdayheseemedtosmile19evenwalktaller.It'samazingwhatarealnodof20candotoliftpeopleup. 1A.minutes B.seconds C.hours D.years 2A.nothing B.everything C.something D.onething 3A.after B.ago C.before D.during 4A.toy B.car C.vehicle D.bike 5A.writing B.reading C.hearing D.explaining 6A.tookup B.pickedup C.heldup D.gaveup 7A.simply B.deliberately C.evidently D.correctly 8A.plot B.scene C.idea D.story 9A.back B.in C.out D.down 10A.quit B.stop C.argue D.think 11A.remaining B.remained C.spotted D.losing 12A.designed B.bought C.decorated D.received 13A.what B.that C.which D.why 14A.onceinawhile B.innotime C.fromthenon D.againandagain 15A.referto B.applyto C.relyon D.spyon 16A.hands B.heads C.mouths D.feet 17A.or B.and C.but D.because 18A.less B.worse C.more D.much 19A.larger B.happier C.luckier D.broader 20A.approval B.achievement C.judgment D.comfort
设集合A={x∈Z|x2≤1}B={-1012}则A∩B=
Nearly20U.S.stateshavestartedcarryingoutformerpresidentBarackObama'sCleanPowerPlanwhichplaceslimitsoncarbondioxideemissionsfrompowerplantsinanefforttoreducetheimpactsofclimatechange.Theplanhasbeeninlegallimbo边缘forthepastyear.Yetscientistshavenowcalculatedanotheroutcomeofthepolicyharmtocrop沁Ids产童iftheplaniscancelled.Alongwithcarbonpollutioncoal-firedpowerplantsspew喷出pollutantsthatformwhatweknowassmog.Thecontributionofsmogtoincreasedratesofasthma哮喘andprematuredeathswasalreadyknown.Thenewresearchestimatestheextenttowhichsmogunderair-pollutionpolicies-inplacebeforetheCleanPowerPlanwouldlimitproductionin2020offourmajorcropscomcottonpotatoesandsoybeans. LedbyenvironmentalengineerShannonL.CappsnowatDrexelUniversitytheteamalsosketchedtheextenttowhichthosecropproductionlosseswouldreduceunderthreenationwidescenarios方案.Oneimprovedtheefficiencyofindividualpowerplants.AnothermodeledapolicysimilartotheObamaplansettingstateCO2emissionsgoalsfortheelectricitydepartment.Athirdestablishedataxoncarbonemissionsunderwhichemissionsfellthemost.Butthegreatestdropinsmog-formingpollutants-andgreatestgainsincropyields-camefrompoliciessuchastheCleanPowerPlan. ResearcherscalculatedhowwelleachscenariowouldreducethepotentialproductivitylossPPLofeachcrop.PPLisaprojectedvaluefor2020andindicateshowmuchcropgrowthwouldsufferbecauseofsmog.Scenario2mostcloselyagreeswithresultsexpectedfromtheCleanPowerPlan. 1What'sthemainpurposeofTheCleanPowerPlan? A.Tooffercleanpower. B.TolimitCO2emissions. C.Toslowclimatechange. D.Toincreasecropproduction. 2Thelatestresearchshowsthatsmogmaycause. A.asthma B.earlydeaths C.heartdisease D.cropproductionloss 3WhatcanweinferfromParagraph2? A.Scenario3wasintendedtoincreasetaxes. B.Scenario2increasedcropyieldsmost. C.ScenarioIdidn'thaveanyeffectoncropyields. D.ThethreescenariosweremadeatDrexelUniversity. 4What'sthebesttitleofthepassage? A.U.S.statesrestarttheObama'sPlan. B.TheCleanPowerPlanwascalledoff. C.Threescenariosbenefitcropyields. D.Smogdoesharmtopeople'shealth.
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来写的以下作文.文中共有10处语言错误每句中最多有两处.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∧并在其下面写出该加的词. 删除把多余的词用\划掉. 修改在错的词下画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. Haveyoueverhadheadacheduringatest?Haveyoueverbeentooconcernedaboutsomethingthatyouevencan'tsleepatnight?Ifsothenyouknowthatstressis.Toomuchstresscanresultinangrydepressionandotherrelatedproblemswhichweneedtotakethemseriously. Howevernotallstresswasharmfultoyou.Somekindsofstresscanhelpyougettingthingsdonebetterlikewhenyouarerunningtowardsthefinishinglineorwhenyouareaskingtodeliveraspeechtoyourclass.Stresssometimescanpushyoutomakefullpreparationsforatest. Thebestapproachofreducingstressistohaveabalancedlife.Ifyougetenoughsleepeatpropertakemoreexerciseandhaveenoughfuntimeyoumightfeellessstressed.
已知函数fx=x+过点10作曲线fx的两条切线切点为Ax1fx1Bx2fx2其中0<x1<x2.若在区间x1x2中存在唯一整数则a的取值范围是
It'sasadrealitythatmanyofusfindourselvesjusttoobusytocontributetoourcommunities. Foralongtime1toobelieveditcosttoomuchintimemoneyand1tomakearealdifference.ButallthatchangedwhenI2mygood-deed-a-dayproject. MydaughterEmilywasmyprimary3.Iwantedtoshowherwecoulddolittlethingstohelpothersandbe4. ThefirstweekIwasn'tsureifIcould5it.IsurfedtheInternetforideas.OnedayI6ablindmaninthesubwaystation.He7ashethankedme.AnotherdayIbroughtflowersfrommygardentoa8nursinghome…IcouldonlyhopeIwasarousing9inothers. Afterjustafewdays10IfounditeasierthanI'dexpected.IknewIwasmakinga/an11 EveryeveningatthedinnertableI12thatday'sgooddeedtoEmily.Emilybegan13whatI'dstarted.Onawalkhomefromschoolshe14toaneighbour'spotofgeraniums天竺葵whichhadtoppled摇晃inthewindandsetitright.Thatwasmygooddeedfortheday!sheyelled.Anotherdayshehelpedmecollect15fromourneighboursforthefoodbank.Wedroppedoffthefoodand16wedroveawayEmilyannounced17thatshewantedtoworkthereoneday. BythelastweekIknewI'dchanged.AtfirstIhadn'tbeenentirely18thatIcoulddoagooddeedeveryday.Nowitwaspracticallysecond19.IfeltagreaterresponsibilitytotakeactionwhenIsawaneed20lookingtheotherway.IfeltasthoughI'dawakenedsomehow. 1A.energy B.space C.wisdom D.salary 2A.stopped B.started C.forgot D.remembered 3A.donation B.expectation C.celebration D.inspiration 4A.lucky B.clever C.happy D.merciful 5A.get B.manage C.put D.appreciate 6A.watched B.waited C.guided D.ordered 7A.smiled B.sighed C.frowned D.jumped 8A.popular B.distant C.deserted D.local 9A.interest B.mercy C.awareness D.praise 10A.though B.besides C.therefore D.also 11A.discovery B.difference C.mistake D.fortune 12A.reminded B.pointed C.recalled D.described 13A.criticizing B.sharing C.laughing D.praising 14A.marchedover B.pulledover C.turnedover D.fellover 15A.money B.vegetables C.donations D.clothes 16A.before B.since C.until D.as 17A.proudly B.eagerly C.anxiously D.casually 18A.concerned B.convinced C.expected D.persuaded 19A.scene B.language C.nature D.skill 20A.bymeansof B.regardlessof C.aswellas D.insteadof
Howtopersuadepeople Convincingpeoplethatyourwayisthebestwayisoftenverydifficult-especiallywhenyou'renotquitesurewhythey'resayingno.Thetrickistogetthemwonderingwhythey'resayingno.1. Understandhowtimingiseverything.Knowinghowtopersuadepeopleisn'tjustinwordsandbodylanguage-it'salsoinknowingtherighttimetotalktothem.2youwillmostlikelyachievefasterbetterresults. Gettoknowthem.Alargepartofwhetherornotpersuasioniseffectiveisbasedonthegeneralrelationshipbetweenyouandyourclient/son/friend/employee.Ifyoudon'tknowthepersonwellit'svitaltostartbuildingthisrelationshipimmediately-findcommongroundassoonaspossible.Humansingeneralaremorefondofpeoplethataresimilartothem.3. 4.Peoplearemorepersuadedbyafastconfidenttalkerthanaccuracy.Thefasteryoutalkthelesstimeyourlistenerhastoprocesswhatyou'vesaidandquestionit.Youmaycreatethefeelingthatyoutrulygraspthesubjectbyrunningthroughthefactsatwarpspeedconfidentofthemall. Createurgency.Inordertogetpeopletoactinthemomentyouhavetobeabletocreateasenseofurgency.5it'sunlikelythey'llchangetheirmindsinthefuture.Youmustpersuadepeopleinthepresentit'sallthatmatters. A.Talkfast B.Communicatewithothers C.Ifsomeoneisawareofthis D.Andwiththerighttricksyoucandoit E.Sofindparallelsandmakethemknown F.Ifthey'renotmotivatedenoughtowantwhateveryouhaverightnow G.Ifyouapproachpeoplewhentheyaremorerelaxedandopentodiscussion
Withthe1inventofpersonalcomputerstheInternetandcellphonespeoplenowhavemoreimmediateaccesstoothersandinformation2anytimeinhistory.Losingthataccesscanleadtodisconnectanxiety''3isapsychologicaltermusedtodescribethe4anxietyfeelingsthatpeopleexperiencewhentheyareunable5usetheircellphonesorcannotlogontotheInternet.Somepeople6affectbydisconnectanxietymaystarttofeelupsetwhen7cannotreachtheirfriendsonline.Othersgetreallyworriedwhentheyarenotabletorespondtoemergenciesandthismakesthemfeel8help.Stillothersaresodependentontheircellphonesthattheyarefrightenedofmissinganyphonecalls.CellphonesandtheInternet9becomethemostimportanttechnologicaltoolstothesepeoplewhocannotaffordtolive10thesethings.
如图在以P为顶点母线长为的圆锥中底面圆O的直径AB长为2C是圆O所在平面内一点且AC是圆O的切线连接BC交圆O于点D连接PDPC. 1求证平面PAC⊥平面PBC 2若E是PC的中点连接OEED当二面角B-PO-D的大小为120°时求平面PAC与平面DOE所成锐二面角的余弦值.
在平面直角坐标系xOy中曲线C的参数方程为α为参数直线l的参数方程为t为参数0≤β<π以坐标原点O为极点x轴的非负半轴为极轴建立极坐标系. 1求曲线C的极坐标方程 2已知直线l与曲线C相交于AB两点且|OA|-|OB|=2求β.
FormostofherlifeSuanneLaqueur'spassionforstorytellingwasshownonthedancefloor. AlthoughLaqueurbeganwritingatayoungagedancingalwaystookcenterstage.ShemajoredindanceandtheateratAlfredUniversityandtaughtathermother'sdancestudioinCroton-on-HudsonNewYorkforyears.ButwhenhermotherwasreadytoretireandanopportunityopenedforLaqueurtotakeoverthestudiosherealizedshehadnointerestintakingonthebusinesssideofherartOwningastudioisalotofwork-financiallylogistically.Ilovetheteachingthechoreographing编舞thestagingbutIdidn'twanttoownit. YetLaqueur'sdisinterestinrunningthestudiochangedwhenshebecameaself-publishedauthor.Inthefallof2013shedecidedtopursueSelf-publishingasawayofsharingherfirstcompletednovelwithfriendsandfamily.Duringtheprocesssherealizedthatfollowinghertruepassion-tellingstoriesthroughwriting--madethebusinessoftheartworthwhileandowningthatbusinessmeantshecoulddirectherwritingcareerhowevershechose. Startingwithhersecondself-publishednovelshebeganinvestingmoretimeinmarketingandbuildingheraudience.Herinvestmentpaidoff.Since2014Laqueurnow49hasself-publishedsixnovelswhichcollectivelyhavehundredsofratingsandreviewsonGoodreads.Her2016novelAnExaltationofLarksstoletheshowatthe25thAnnualWriter'sDigestSelf-PublishedBookAwardstoppingmorethan2300entriestowinthegrandprize. YouhavetowritethemosttruthfulstorytoyouandIthinkself-publishingallowsthatfreedomshesays.Ifyouworkwithtraditionalpublishingit'smoreaboutwhat'smarketable.Therearetrade-offswhicheveryonewilltellyoubutbyself-publishingIhavecontrolofthebookIhavecontrolofthestoryandI'mcoolwiththat. 1FromParagraph2wecanlearnthatLaqueur• A.wantedtoownapublishinghouse B.didn'tliketeachingdancinginfact C.wasapart-timewriterwhenshewasyoung D.wasinterestedinrunninghermother'sstudio 2WhatmadeLaqueurchangeherattitudetobusiness? A.Hermother'spersuasion. B.Self-publishinghernovels. C.Thedesiretomakemoney. D.Herownpassiontowardart. 3WhichofthefollowingcanbestreplacethephrasestoletheshowinParagraph4? A.becameafailure. B.wasshowntopeople. C.gotalltheattention. D.wasaccidentallystolen. 4WhatcanbeinferredfromwhatLaqueur'ssaid? A.Sheenjoysthewayofself-publishing. B.Shewillneverusetraditionalpublishing. C.Traditionalpublishingonlyfocusesonthemarket. D.Self-publishingwillreplacetraditionalpublishing.
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