首页
试卷库
试题库
当前位置：
X题卡
>
所有题目
>
题目详情
查看本题答案
包含此试题的试卷
教案备课库《》真题及答案
点击查看
你可能感兴趣的试题
热门试题
更多
古代数学著作九章算术有如下的问题“今有女子善织日自倍五日织五尺问日织几何”意思是“一女子善于织布每天织的布都是前一天的2倍已知她5天共织布5尺问这女子每天分别织布多少”根据上述已知条件若要使织布的总尺数不少于30尺则至少需要
下列说法正确的是
如图所示将一矩形花坛ABCD扩建成一个更大的矩形花坛AMPN要求B点在AM上D点在AN上且对角线MN过C点已知AB=3米AD=4米． 1要使矩形AMPN的面积大于50平方米则DN的长应在什么范围 2当DN的长为多少米时矩形花坛AMPN的面积最小并求出最小值．
下列相关实验示意图不能达到实验目的是
WhyDoPeopleBlinkTheirEyes Peopleblink眨眼theireyestensofthousandsoftimeseveryday．Scientistshavelongbelievedblinkingwasaninvoluntarymovementandservedmainlytokeeptheeyeballswet．Butanewstudysuggestsithasamoreimportantpurpose． AninternationalteamofscientistsfromtheUniversityofCaliforniaatBerkeleystudiedtheblinkingofhumaneyelids．ThejournalCurrentBiologypublishedtheirfindings．Theteamsaidtheyfoundthatblinkingrepositionsoureyeballssowecanstayfocusedonwhatweareseeing．Theysaidthatwhenweblinkoureyelidstheeyesrollbackintotheirsockets﹣thebonyareathatsurroundsandprotectstheeyes．Howevertheresearchersfoundtheeyesdon'talwaysreturntothesameposition．Theysaidthiscausesthebraintotelltheeyemusclestoreorganizeoureyesight． GerritMausistheleadwriterofthereport．HeservesasanassistantprofessorofpsychologyatNanyangTechnologicalUniversityinSingapore．MaussaidOureyemusclesarequitesluggish迟缓的andimprecisesothebrainneedstoconstantlyadaptitsmotorsignalstomakesureoureyesarepointingwherethey'resupposedto．Ourfindingssuggestedthatthebrainmeasuresthedifferenceinwhatweseebeforeandafterablinkandcommandstheeyemusclestomaketheneededcorrections．Theresearcherssaidthatwithoutsuchcorrectionsoursurroundingswouldappearunclearandevenjumpy．Theysaidthemovementactslikeasteadicam摄影稳定器ofthemind． Theresearcherssaidtheyaskedvolunteerstositinadarkroomwhilestaringatasmalldotonaflatsurface．Theyusedspecialcamerastofollowthevolunteer'sblinksandeyemovements．Aftereachblinkthedotwasmovedonecentimetertotheright．Thevolunteersdidnotnoticethisbutthebraindid．Itfollowedthemovementanddirectedtheeyemusclestorefocusonthedot．Afterthedotwasmovedinthisway30timesthevolunteers'eyeschangedtheirfocustotheplacewheretheypredicteditwouldbe． ProfessorMaussaidEventhoughparticipantsdidnotconsciouslyregisterthatthedothadmovedtheirbrainsdidandadjustedwiththecorrectiveeyemovements．Thesefindingsaddtoourunderstandingofhowthebrainconstantlyadaptstochangescommandingoureyemusclestocorrectforerrorsinourbodies'ownhardware． 63．AccordingtothenewstudyblinkingeyescanB． A．servetokeeptheeyeballswet B．repositioneyeballstostayfocused C．consciouslycorrecteyemovements D．makeoureyesadapttomotorsignals 64．FromtheexperimentwecanlearnthatD． A．volunteerscouldseethemovingdotwithspecialcameras B．theeyeballscouldstayintheplaceastheywerepredicted C．participantswereawareofthedot'smovementstotheright D．thebraincommandedtheeyemusclestorefocusonthedot 65．TheunderlinedwordregisterinParagraph5probablymeansA． A．realizeB．refocusC．reserveD．reason 66．ThispassageshowsthatC． A．eyemusclesarequiteinactiveandimprecise B．theresearchisofgreatvalueintheeyemovement C．thebrainplaysanimportantroleinseeingthingsclearly D．volunteerscontroltheirblinkstofollowthechangesofthedots．
已知数列{an}中a1=1a2n=n-ana2n+1=an+1则a1+a2+a3+…+a99=．
FacebookIsaBigWaster Duringthefirstdecadeofthe21stcenturyapopularandnewwordhascomeintoourvocabulary﹣Facebook．ThisisthemostpopularsocialnetworkingwebsiteontheInternet．71GYoucansendmessagestoyourfriend'selectronicwallputupastatussayingsomethinglikeGoingtothemallIneedtogetanewpairofshoesorit'sfinallytheweekend!． Inspiteofthebenefititdoesoncommonpeopleitistruethatthissocialnetworkisabigwaster．Thereareabout350millionactiveusersonthiswebsiteand67%ofthemarebetweentheagesof13﹣25．Morethan35millionusersupdatetheirstatuseveryday．72A ThehighestagegroupwhouseFacebookareteenagers．Mostofthemkeepthewebsiterunningwhenevertheyareusingthecomputeriftheyaren'tinschoolorwhentheyaren'tasleep．Facebookisjustchangingthenewgenerationofyoungstersunconsciously．Theteenagelifeisoneofthemostimportantstagesoflife73BItisadistractiontotheirmindaswell．NowadayswhenalltheirhomeworkandresearchareonICT信息技术theywouldeasilyswitchtoFacebookjusttocheckiftherewasanythingupdatedamongtheirfriends． Facebookisalsowherepeoplecanseethegossipamongtheirfriendsvirtualargumentsrelationshipstatusandupdateswhoisinwhosetopfriendsyoucanbecomefanofanythingjoingroupspostpicturesandvideosplaychildishgamesinvitefriendstopartiesoreventsandalotmore．Generallyallthesewouldjustdisturbpeopleintolivinglifetothefullest．It'snotjustteenswhobecomeaddictedevengrown﹣upsdo．Anaveragepersonspendsabout55minutesonFacebook．74CTechnologymightbetakingoverpeople'slife．FurthermorepeoplewhouseFacebookthroughtheirmobilephonesare50%moreactiveonFacebookthannon﹣mobilephoneusers．ThisshowspeopleusingFacebookontheirphonesaswellascomputersjustcan'tstandbeingawayfromthewebsite．Facebookislikecracktosomefolk． 75DThiswouldmakethemthinkhowlifeislikewithoutsayingwhat'sontheirmindtoalltheirfriendsontheInternet．Abreakwouldalsomakethemmoreactivelikesocializinginperson．Thiswouldfinallyhelpthemfocusbetterinschoolorinwork．Althoughabout80%ofpeoplewhotakeabreakwouldcomebacktoFacebookwithindays． A．And2.5billionphotosareaddedeachmonth． B．WastingitonFacebookisnotencouraginginanyway． C．Thisstatisticisn'tthatbadbutsomepeoplespendabout3﹣5hours． D．ItistimepeopleshouldtakeabreakfromFacebookonceinawhile． E．AsaresulttheaverageFacebookusershave130friendswhotheysharelinkswith． F．UsuallywhenpeoplehearthewordssocialnetworkingtheirbrainsautomaticallygotositessuchasTwitterorFacebook． G．ThemainideaofFacebookisthatyoucankeepintouchwithallyourfriendsaroundtheworldwhohaveFacebook．
已知碳酸钙的分解①CaCO3s═CaOs+CO2g仅在高温下自发氯酸钾的分解②2KClO3s═2KCls+3O2g在任何温度下都自发下面有几组焓变数据其中可能正确的是
下列过程或现象与盐类水解无关的是
在△ABC中角ABC的对边分别为abc已知cosB=sinA+B=ac=2． 1求sinA的值 2求b和c的值．
CherishtheMomentswithOurParents Therewassomethinginanelderlywoman'sbehaviorthatcaughtmyeye．UnsureofherstepsthewomanmovedslowlyalongwithayoungerwomanwhoIguessedwasherdaughter．Thedaughterwasrollinghereyesandcheckingherwatcheveryfewseconds． TheolderwomanlefttheyoungeroneandbegantotickthroughtheDVDsonthenearestshelf．WithouthesitationIwalkedoverandaskedifIcouldhelpherfindsomething．Thewomansmiledatmeandshowedmeatitleonapieceofpaper． RatherthanrushofftolocatetheDVDforthewomanIaskedhertowalkwithmesoIcouldshowherwhereshecouldfindit．LookingbackIthinkIwantedtoenjoyhercompanyforamoment．HermovementsremindedmeofmyownmotherwhohadpassedawaythepreviousChristmas． Aswewalkedthewomanseemedgladoftheunrushedcompanyandcasualconversation．Wefoundthemovieandshetoldmeitwastheoneshe'denjoyedwhenshewasherson'sageandthatshehopedhewouldenjoyitasmuchasshehad．Maybeshesaidhecouldenjoyitwithhisownyoungchildren． Iaccompaniedhertothequeueatthecashier．AsthecashierputtheDVDintoaplasticbagIwentovertotheyoungerwomanwhowasstilltappingherfootatthefrontofthestore． IsthatyourmomIasked． Ihadexpectedhertotellmeitwasnoneofmybusiness．ButsherolledhereyesandsaidYeah．Therewasannoyanceinherreply．StillwatchingthemotherIsaidMindsomeadvice Goaheadsaidthedaughter． IsmiledtoshowherIwasn'tcriticizingCherishherIsaidWhenshe'sgoneit'sthelittlemomentsthat'llcomebacktoyou．Momentslikethis．Iknow． Itwastrue．ImissedmymomstillandrememberedwithsadnessthemomentswhenI'dusedmyimpatiencetomakeherlifemiserable． Theelderlywomanmovedslowlybacktoherdaughter．Togethertheymadetheirwaytowardthestore'sexit．Theystoodthereforamomentsidebysidewatchingtherushoftheholidaycurrent．Thenthedaughterglancedoverandslowlyplacedherarmwithapparentlyunaccustomedaffectionaroundhermother'sshouldersandgentlyguidedherhome． 56．ThedaughtercheckedherwatchfrequentlybecausesheC． A．hadtowaitforafriend B．wantedtobuyanewwatch C．wasimpatienttoshopwithhermom D．wasuninterestedinwatchingtheDVD 57．FromParagraphs3and4weknowthatD． A．theelderlywomanhadn'tseenthemoviebefore B．theelderlywomanfoundherson'sfavoritemovie C．theauthorandtheeldlywomanhurriedtofindtheDVD D．theauthorandtheelderlywomanenjoyedeachother'scompany 58．WecanlearnfromthepassagethatD． A．theauthorhadtreatedhermomverywell B．theelderlywomanlookedliketheauthor'smom C．theauthorscoldedthedaughterforherbehavior D．thedaughterchangedherattitudetowardhermom．
在△ABC中角ABC对应的边分别是abc已知A=60°a=4b=4则B等于
假设你是红星中学高三1班的学生李华．下面四幅图描述了你们带留学生Jack看中医TCM的经历．请你根据图片的先后顺序为校刊英语角写一篇短文介绍你们带Jack看医生前后的全过程． 注意词数不少于60． 提示词把脉feelone'spulse
已知四棱锥PABCD中PD⊥平面ABCD四边形ABCD是正方形E是PA的中点． 求证1PC∥平面EBD 2平面PBC⊥平面PCD．
以点12为圆心且经过点20的圆的方程为
为了评估AB两家快递公司的服务质量现从两家公司的客户中各随机抽取100名客户作为样本进行服务质量满意度调查现将AB两公司的调查得分分别绘制成频率分布表和频率分布直方图．规定60分以下为对该公司服务质量不满意． Ⅰ求样本中对B公司的服务质量不满意的客户人数 Ⅱ现从样本对AB两个公司服务质量不满意的客户中随机抽取2名进行走访求这两名客户都来自于B公司的概率 Ⅲ根据样本数据试对两个公司的服务质量进行评价并阐述理由．
如图长方体ABCD-A1B1C1D1中∠DAD1=45°∠CDC1=30°那么异面直线AD1与DC1所成角的余弦值是
已知点A-a0Ba0a＞0点C在圆x-22+y-22=2上且满足∠ACB=90°则a的最小值是．
COCl2俗名称作光气是有毒气体．在一定条件下可发生的化学反应为COCl2g⇌COg+Cl2g△H＜0下列有关说法不正确的是
已知圆Mx2+y2=l． Ⅰ求过点-l-2的圆M的切线方程 Ⅱ设圆M与x轴相交于AB两点点P为圆AM上异于AB的任意一点直线PAPB分别与直线x=3交于CD两点． i当点P的坐标为01时求以CD为直径的圆的圆心坐标及半径 ii当点P在圆M上运动时以CD为直径的圆被x轴截得的弦长是否为定值请说明理由．
点A3-4与点B-18关于直线l对称则直线l的方程为．
直线x-y+3=0的倾斜角是
某四棱锥的三视图如图所示如果网格纸上小正方形的边长为l．那么该四棱锥最长棱的棱长为．
已知点Ax02和点B234且|AB|=则实数x的值是
过点A02且与直线x+y+1=0垂直的直线方程为．
在正方体ABCD-A1B1C1D1中当点E在B1D1与B1D1不重合上运动时总有 ①AE∥BC1②平面AA1E⊥平面BB1D1D ③AE∥平面BC1D④A1C⊥AE． 以上四个推断中正确的是
若直线l1ax+y-l=0与直线l2x+ay+l=0平行则a的值为
已知底面边长为1侧棱长为2的正四棱柱的各顶点均在同一个球面上则该球的体积为
在△ABC中角ABC对应的边分别是abc已知A=60°b=1△ABC的面积为则△ABC外接圆的直径为
已知两条直线mn两个平面αβ下面说法正确的是
热门题库
更多
教案备课库
教案备课库
教案备课库
教案备课库
教案备课库
教案备课库
教案备课库
教案备课库
教案备课库
教案备课库
教案备课库
教案备课库
教案备课库
教案备课库
高一上学期英语
高一下学期化学
湘公网安备 43130202000226号