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如图,在菱形ABCD中,AC、BD交于点O,BC=5,若DE∥AC,CE∥BD,则OE的长为
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如图菱形ABCD的对角线ACBD相交于点O.E.为AD的中点若OE=3则菱形ABCD的周长为
如图在▱ABCD.中对角线ACBD交于点O.点E.点F.在BD上且BE=DF连接AE并延长交BC于点
如图菱形ABCD的周长是20对角线ACBD相交于点O.若BD=6则菱形ABCD的面积是
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如图在▱ABCD中对角线AC与BD交于点O.若增加一个条件使▱ABCD成为菱形下列给出的条件不正确的
AB=AD
AC⊥BD
AC=BD
∠BAC=∠DAC
.如图4在菱形ABCD中对角线AC与BD相交于点O.AC=8BD=6OE⊥BC垂足为点E.则OE=_
如图菱形ABCD中对角线ACBD相交于点O.若AB=5AC=6则BD的长是
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如图在菱形ABCD中AC.BD相交于点OE为AB的中点若OE=2则菱形ABCD的周长是.
如图在菱形ABCD中对角线AC与BD相交于点O.AC=8BD=6OE⊥BC垂足为点E.则OE=▲.▲
如图在菱形ABCD中对角线AC与BD相交于点OAC=8BD=6OE⊥BC垂足为点E则OE=.
如图.在菱形ABCD中对角线ACBD交于点O.下列说法错误的是
AB∥DC
AC=BD
AC⊥BD
OA=OC
如图菱形ABCD的对角线ACBD交于点O.其中AC=8BD=6以OCOB为边作矩形OBEC矩形OBE
如图四边形ABCD是菱形对角线ACBD相交于点O.且AB=2.1求菱形ABCD的周长2若AC=2求B
如图在菱形ABCD中对角线ACBD相交于点O.E.为BC的中点若菱形的周长为80则OE=______
如图在菱形ABCD中对角线AC与BD相交于点O.AC=8BD=6OE⊥BC垂足为点E.则OE=.
如图已知菱形ABCD的边长为5对角线ACBD相交于点O.BD=6则菱形ABCD的面积为.
如图在菱形ABCD中对角线AC.BD相交于点O.作OE∥AB交BC于点E.则OE的长一定等于
BE
A O
AD
OB
如图已知菱形ABCD中对角线ACBD交于O点AB=10BD=12则AC=.
如图在菱形ABCD中对角线AC与BD相交于点O.AB=5AC=6.过点D.作DE∥AC交BC的延长线
如图在菱形ABCD中对角线AC与BD相交于点O.过点D.作DE∥AC交BC的延长线于E.1求证OC=
如图在菱形ABCD中对角线AC.BD相交于点O.AB=5AC=6过点D.作AC的平行线交BC的延长线
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过抛物线x2=8y的焦点F作倾斜角为锐角的直线l与抛物线相交于AB两点M为线段AB的中点O为坐标原点则直线OM的斜率的取值范围是.
阅读下面短文掌握其大意从每题所给的ABCD四个选项中选出最佳选项并在答题卡上将该项涂黑. MyyoungerbrotherwouldbeleavingforcollegeandIwasleavingforanewjobinEurope.Weonlyhadafewpreciousmonthsleftasafamilylivingunderthesame41.Everythingwouldchangeinthe42. Afamilyofmagpies喜鹊43inourmapletree.Thisfamilyseemedtobeextraordinarilylively.Oneearlymorningthenoisewasso44thatmydadwentouttoseewhatthebirdsweredoing.Hefoundayoungmagpie45aroundtheyardflapping拍打hislittlewingsandyelling. DadlookedupinthetreetofindMommyandDaddyMagpiesittingonabranchandglaring46athim.Hehadtodosomethingforthepoorlittlething.Dadcalledthezoofor47.Theytoldhimnotto48itandassuredhimthebabywouldlearntoflyonitsown.Dadnolonger49themagpiearoundtheyard.Hedidhoweverwatchhim50fromthelivingroomwindowjusttomakesureacatdidn'tturnhiminto51. ThenextdayIgota52atmysummerjob.Itwasfrommyfather.Henevercalledme53.HeaskedmeifIsawMoreybeforeIlefthome﹣henamedthebirdMorey. DrivinghomefromworkI54itwasn'tonlyaboutthemagpiebutalsoabouthisownlittlefledglings幼鸟whowere55thenest.Itwasaboutmybrotherandme.DadfeltashelplessastheMommyandDaddybirdwatchinginthetree.Hecouldn'tmakeusflynorcouldhe56catsonceweleftthenest. Igothomeandfoundhimlookingoutofthekitchenwindowwith57inhiseyes.I58himbysayingMoreymighthavelearnttoflywithverygoodparentsraisinghim. SoonitwastheendofAugust.Bagswere59anditwastimeformybrotherandmetoleavethenest.IntheendDadhadnothingtoworryabout.He60hislittlefledglingswell.Andweflew… 41.A.house B.roof C.family D.room 42.A.fall B.spring C.winter D.summer 43.A.cutdown B.tookdown C.settleddown D.broughtdown 44.A.exciting B.low C.frightening D.loud 45.A.flying B.wandering C.running D.jumping 46.A.helplessly B.carefully C.hopefully D.suddenly 47.A.advice B.permission C.leave D.conclusion 48.A.hunt B.touch C.ignore D.chase 49.A.helped B.assisted C.followed D.collected 50.A.coldly B.cautiously C.purposely D.gladly 51.A.taste B.nest C.meat D.lunch 52.A.call B.message C.news D.notice 53.A.athome B.atschool C.atwork D.atnoon 54.A.summarized B.wondered C.realized D.questioned 55.A.building B.leaving C.directing D.quitting 56.A.driveaway B.fightagainst C.arguewith D.associatewith 57.A.light B.doubts C.pain D.tears 58.A.greeted B.comforted C.persuaded D.hugged 59.A.locked B.strengthened C.loaded D.packed 60.A.brought B.loved C.raised D.accompanied
在直角坐标系xOy中已知曲线C的参数方程为θ为参数. Ⅰ以原点O为极点x轴正半轴为极轴建立极坐标系求曲线C的极坐标方程 Ⅱ设AB为曲线C上两动点且OA丄OB求|AB|的取值范围.
某种活性细胞的存活率y%与存放温度x℃之间具有线性相关关系样本数据如表所示 经计算得回归直线的斜率为﹣3.2.若存放温度为6℃则这种细胞存活率的预报值为%.
在△AOB中OA=OB=1OA⊥OB点C在AB边上且AB=4AC则=
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设变量xy满足约束条件则z=x﹣y的取值范围为
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已知且2sin2α<0则的值为
已知函数y=ex的值域为集合A不等式x2﹣x﹣6<0的解集为集合B则A∪B=
设ab∈01∪1+∞定义运算则
下列命题中真命题的是
设i为虚数单位且则x=.
已知命题p∃x0>0x0+a﹣1=0若p为假命题则a的取值范围是
在一定温度下将6molCO2和8molH2充入2L恒容密闭容器中发生反应CO2g+3H2g⇌CH30Hg+H2OgAH<O一段时间后达到平衡.反应过程中测定的数据如下表.下列说法正确的是
化学与生产生活和社会可持续发展密切相关.下列说法不正确的是
若函数的图象相邻的两个对称中心为将fx的图象纵坐标不变横坐标缩短为原来的得到gx的图象则gx=.
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