- 问题详情:如图,圆内接四边形ABCD是由四个全等的等腰梯形组成,AD是⊙O的直径,则∠BEC的度数为( )A.15° B.30° C.45° D.60° 【回答】B知识点:正多边形和圆题型:选择题...
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- 问题详情:Lukedidn’tknowwhattodo.HewantedtoyellatKyle,his 36 ,becauseKylecontinuedto 37 withhismom,Jane.Shedidn’t 38 verymuchfromhim.Shetriedtogetitintohisheadthatshedidn’thavethe 39 forhiscollegeeducation.Notacentcouldbeexpected! 40...
- 18053
- 问题详情:Ifyouwalkintoaroomwithbluewalls,youwillfeel ,becauseblueisaclamcolour. A.excited B.stressed C.relaxed D.surprised【回答】C知识点:相似相近词比较题型:选择题...
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- 问题详情:如图23,在△AFD和△BEC中,点A、E、F、C在同一条直线上,有下面四个论断:(A)AD=CB,(B)AE=CF,(C)∠B=∠D,(D)AD∥BC.请用其中三个作为条件,余下一个作为结论,遍一道数学题,并写出解答过程. 【回答】*不惟一.如:已知:AE=CF,∠B=∠D,AD∥BC.求*:AD=BC.等等;知识点:三角形全等的判定题型:解答题...
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- 问题详情:如图,已知△BEC是等边三角形,∠AEB=∠DEC=90°.AE=DE,AC、BD的交点为O. (1)求*:△AEC≌△DEB; (2)若∠ABC=∠DCB=90°,AB=2cm,求图中*影部分的面积.【回答】(1)*略 (2)解:连结EO并延长EO交BC于点F,连结AD.由(1),知AC=BD.∵∠ABC=∠DCB=90°,∴∠ABC+∠DCB=180°,AB∥DC,AB==CD,∴四边形ABCD...
- 25266
- 问题详情:如图,∠BCA=α,CA=CB,C,E,F分别是直线CD上的三点,且∠BEC=∠CFA=α.请判断EF,BE,AF三条线段之间有怎样的数量关系,并*.【回答】解:EF=BE+AF.理由如下:∵∠BEC=∠CFA=α=∠BCA,∠BCA+∠BCE+∠ACF=180°,∠CFA+∠CAF+∠ACF=180°,∴∠BCE=∠CAF,在△BCE和△CAF中,...
- 10041
- 问题详情:如图,E是矩形ABCD的对角线的交点,点F在边AE上,且DF=DC,若∠ADF=25°,则∠BEC=______.【回答】115° 知识点:特殊的平行四边形题型:填空题...
- 25964
- 问题详情:单句语法填空1.—Whydidyoumakethekiteofclothinsteadofpaper?—Becausepaper____________(tear)easily.2.Theyoungmanglared____________thenaughtyboysandtheykeptsilentatonce.3.Thelibraryrequires____________(clean),butit’llhavetowaituntilSunday.4.You’dbe...
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- 1、BEC[BusinessEnglishCertificate]2、CambridgeUniversityBECPracticeTests3、I'vepassedBECPreliminary/Vantage/HigherLever.4、FeaturesofBECCourseandtheTeachingPractice5、Believeitornot,nowIdobelievethetrustinessofBECandIamplanningtochallengetheBECHighe...
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- 问题详情:已知:BE⊥CD于E,BE=DE,BC=DA,(1)求*:△BEC≌△DEA;(2)求*:BC⊥FD.【回答】(1)*见解析;(2)*见解析.【分析】(1)根据已知利用HL即可判定△BEC≌△DEA;(2)根据第(1)问的结论,利用全等三角形的对应角相等可得到∠B=∠D,从而不难求得DF⊥BC.【详解】*:(1)∵BE⊥CD,∴∠BEC=∠DEA=90°,在Rt△BEC与Rt△DEA...
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- 问题详情:如图,正方形ABCD内接于⊙D,点E在劣弧AD上,则∠BEC等于( )A.45° B.60° C.30° D.55°【回答】A知识点:点和圆、直线和圆的位置关系题型...
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- 问题详情:ncan’tgotothemeeting hehasabadcold.A. because B.unless C.whether D.although【回答】A知识点:连词题型:选择题...
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- 问题详情:如图,△BAD是由△BEC在平面内绕点B旋转60°而得,且AB⊥BC,BE=CE,连接DE.(1)求*:△BDE≌△BCE;(2)试判断四边形ABED的形状,并说明理由.【回答】(1)*:∵△BAD是由△BEC在平面内绕点B旋转60°而得,∴DB=CB,∠ABD=∠EBC,∠ABE=60°,∵AB⊥BC,∴∠ABC=90°,∴∠DBE=∠CBE=30°,在△BDE和△BCE...
- 12515
- 问题详情:词形转换1.—Why Lily (notsee)thefilmyesterday? —Becauseshe (see)italready.2.Pleasewaituntilshe (come)back.3.Whenyou (phone)melastnight,I (watch)TVwithmyparents.4.—Howlong yourmother...
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- 问题详情:如图,AB∥CD∥EF,∠ABE=38°,∠ECD=110°,则∠BEC的度数为()A.42°B.32°C.62°D.38°【回答】B考点】平行线的*质.【分析】由AB∥CD∥EF,∠ABE=38°,∠ECD=110°,根据平行线的*质,即可求得∠BEF与∠CEF的度数,继而求得*.【解答】解:∵AB∥CD∥EF,∠ABE=38°,∠ECD=110°,∴∠BEF=∠AB...
- 8095
- 问题详情:如图,△ABC≌△DCB,AC与BD相交于点E,若∠A=∠D=80°,∠ABC=60°,则∠BEC等于________.【回答】100°知识点:全等三角形题型:填空题...
- 10218
- 问题详情:MrSmithwillnotbeabletoattendhisson'sweddingceremony,becausehe________animportantspeech.A.willbegiving B.hasgiven C.gives D.willhavegiven【回答】A知识点:非谓语动词题型:选择题...
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- 问题详情: Thenexttimeyoueatapieceofchocolate,besuretoenjoyit,becauseaccordingtotwooftheworld’slargestchocolatemakers—MarsIncandBarryCallebaut,thetreatmaysoonbeinshortsupply.Theproblem?Weareconsumingthecandyatafasterpacethanfarmerscangrowcocoa.Thema...
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- 问题详情:ItwasMother'sDay,buttheyoungmotherwasalittleunhappy,becauseshewas800milesawayfromherthemorningshephonedhermothertowishherahappyMother'sDay,andhermothertoldheraboutthebeautifullilacs(丁香)intherthatday,whenshetoldherhusbandaboutthelilacs,hesai...
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- 问题详情:如图,已知AB,CD,EF互相平行,且∠ABE=70°,∠ECD=150°,则∠BEC=°.【回答】40°.【考点】平行线的*质.【分析】根据平行线的*质,先求出∠BEF和∠CEF的度数,再求出它们的差即可.【解答】解:∵AB∥EF,∴∠BEF=∠ABE=70°;又∵EF∥CD,∴∠CEF=180°﹣∠ECD=180°﹣150°=30°,∴∠BEC=∠B...
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- 问题详情:如图,在⊿ABC中,∠ACB=90°,AC=BC,BE⊥CE于点E,AD⊥CE于点D。求*:(1)⊿BEC≌⊿CDA;(2)DE=AD-BE。【回答】*:(1)∵∠ACB=90°,AD⊥CE ,∴∠CAD=∠BCE …………………1分又BE⊥CE,AD⊥CE ,∴∠ADC=∠CEB…………………2分在⊿CDA与⊿BEC中,…………………4分∴⊿BEC≌...
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- 问题详情:【问题】如图①,在△ABC中,BE平分∠ABC,CE平分∠ACB,若∠A=80°,则∠BEC=__ __;若∠A=n°,则∠BEC=__ _.【探究】(1)如图②,在△ABC中,BD,BE三等分∠ABC,CD,CE三等分∠ACB.若∠A=n°,则∠BEC=____;(2)如图③,O是∠ABC与外角∠ACD的平分线BO和CO的交点,试分析∠BOC...
- 16356
- 问题详情:如图,AB∥CD,CE交AB于点E,EF平分∠BEC,交CD于F.若∠ECF=40°,则∠CFE=________度.【回答】70解析:∵AB∥CD,∠ECF=40°,∴∠AEC=∠ECF=40°,∴∠BEC=180°-∠AEC=180°-40°=140°,∵EF平分∠BEC,∴CEF=∠BEC=×140°=70°,∴∠CFE=180°-∠ECF-∠CEF=180°-40°-70°=70°.故*为70.知识点:平行线的...
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- 问题详情:如图,△ABC中,AB=AC,∠A=36°,DE垂直平分AB,△BEC的周长为20,BC=9(1) 求∠ABC的度数;(3分) (2)求△ABC的周长(3分)【回答】、72° 31知识点:画轴对称图形题型:解答题...
- 27859
- 问题详情:如图,正方形ABCD中,∠DAF=20°,AF交对角线BD于E,交CD于F,则∠BEC=( )A.80° B.70° C.65° D.60°【回答】C知识点:特殊的平行四边形题型:选择题...
- 27715