浙江省温州市育英国际实验学校2019-2020学年第一学期开学考试八年级A班数学检测试卷(含答案)
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温州育英国际实验学校八年级(A 班)3月月考科 学 试 卷亲爱的同学:欢迎参加考试!请你认真审题,积极思考,细心答题,发挥最佳水平。
答题时,请注意以下几点:1.全卷共 页,有四大题, 小题。
全卷满分100分。
考试时间90分钟。
2.答案必须写在答题纸相应的位置上,写在试题卷、草稿纸上均无效。
3.答题前,认真阅读答题纸上的《注意事项》,按规定答题。
4.本卷可能用到的相对原子质量:H -1 C -12 O -16 Ca -405.本卷中的g 取10牛/千克祝你成功!一、选择题(本题有20小题,每小题2分,共40分。
每小题只有一个选项是正确的,不选、多选、错选均不给分)1、夏日炎炎,蚊虫猖獗。
蚊虫叮咬后会在皮肤中释放蚁酸,蚁酸又名“乙酸”,具有一定的腐蚀性,会刺激皮肤红肿起泡。
为缓解症状,适合涂抹的物质是( ▲ )A .食醋B .柠檬汁C .氢氧化钠溶液D .肥皂水2、日常生活中会应用很多化学知识,下列表述中物质的化学性质有关且正确的是( ▲ )A .人体缺铁会导致高血压B .工业上用高锰酸钾加热分解的方法大量制取氧气C .煤燃烧时排放出SO 2和NO 2等污染物在空气中会形成酸雨D .胃酸过多可适量服用氢氧化钙溶液3、假设你是一名营养师,针对下列特定的人群,哪种饮食方案不合理?( ▲ )A .高血压患者的饮食要清淡少盐B .青少年要补充鸡蛋、牛奶,豆制品等蛋白质含量丰富的食物C .贫血患者要补充含钙的无机盐和丰富的蛋白质D .坏血病患者要多吃新鲜的蔬菜和水果4、为便于归纳整理,连续发生的生理活动可用流程图来表示.下列为爱思考的小明同学精心梳理的流程图,其中书写错误的是( ▲ )A .脂肪消化:脂肪→脂肪乳化微粒→甘油+脂肪酸B .平静呼气:膈肌、肋间外肌舒张→胸廓缩小→肺收缩→肺内气压增大→气体出肺C .尿液形成:血液→肾小球→原尿→肾小管→尿液D .体循环:右心室→主动脉→全身各处毛细血管→上、下腔静脉→左心房5、甲、乙两车间排放出的污水中分别含有大量且不同的4种离子,这些离子是Ag+、Ba 2+、Fe 3+、Na+、Cl-、NO 3-、OH-、SO 42-.经检测,甲车间的污水PH >7,则下列判断正确的是( )A .甲车间的污水中可能含有Ba 2+B .乙车间的污水中可能含有Na+C .甲车间的污水中不可能含有SO 42-D .乙车间的污水中一定含有Fe 3+6、由BaCO3和CaCO3组成的混合物,经测定其中碳元素的质量分数为10%,则下列各项中: ①钡元素的质量分数;②钙元素的质量分数;③氧元素的质量分数;④CaCO3的质量分数; ⑤BaCO3的质量分数;⑥BaCO3和CaCO3的质量比,其中能确定的是( )A 、都不能确定B 、只有③能确定C 、只有④⑤⑥能确定D 、都能确定7、有一种含有碳酸钙与氧化钙的混合物,测得其中钙元素质量分数为62.5%.取该混合物 64g 经高温煅烧后,将剩余固体投入足量水中,固体全部溶解生成氢氧化钙,则生成氢氧化钙的质量为( )A.37gB.74gC.148gD.222 g 8、两个或多个同种含氧酸分子之间可以脱水形成相对分子质量更大的酸,如磷酸可形成H 4P 2O 7或H 5P 3O 10等。
浙江省温州市2019-2020学年中考英语第一次联考试卷(含答案)一、听小对话,从A、B、C三个选项中选择符合对话内容的图片。
(共5题,每小题1分)1.When is the school-leavers' party?A. B. C.【答案】C【考点】听录音选图2.What does Lucy do when she meets her teacher?A. B. C.【答案】A【考点】听录音选图3.Which invention does Jerry think is the most important?A. B. C.【答案】C【考点】听录音选图4.Where will Peter and his friend meet tomorrow?A. B. C.【答案】B【考点】听录音选图5.How does Tina improve her English?A. B. C.【答案】A【考点】听录音选图二、听对话,从A、B、C三个选项中选择正确的选项。
(10分)6.听较长对话,完成问题。
(1)What pollution are the two speakers talking about?A. Noise pollution.B. Water pollution.C. Air pollution.(2)What are they going to do to protect the environment later?A. To make a programme.B. To raise some money.C. To make some signs.【答案】(1)B(2)C【考点】长对话理解7.听对话,回答问题。
(1)Why did Mike go to Shanghai?A. To have a test.B. To have a meeting.C. To enter a competition.(2)Who teaches him to sing songs?A. His teachers.B. His parents.C. His friends.(3)How long did he stay there?A. For a week.B. For two weeks.C. For a month.【答案】(1)C(2)B(3)A【考点】长对话理解三、听独白,从A、B、C三个选项中选择正确的选项,完成信息记录表。
2020年八年级创新A 班4月返学考试数学试卷考生须知:本试卷共四页,考试时间120分钟,全卷满分150分.解答题请在答题纸答题区域作答,不得超出答题区域边框线.一.选择题(本题共8小题,每小题6分,共48分) 1.aa a aaa 15462---+-的值为( ) A .是正数 B .是负数 C .是非负数 D .可为正也可为负 2.如图,表示阴影区域的不等式组为( )A .B .C .D .3.若一个三角形的三边和为40,且各边长均为整数,则符合条件的三角形的个数为( ) A .31个 B .32个 C .33个 D .34个 4.若关于x 的分式方程xx x m 2132=--+无解,则m 的值为( ) A .﹣1.5B .﹣0.5C .﹣1.5或2D .﹣0.5或﹣1.55.四条直线y =﹣x ﹣6,y =﹣x +6,y =x ﹣6,y =x +6围成正方形ABCD .现掷一个均匀且各面上标有1,2,3,4,5,6的立方体,每个面朝上的机会是均等的.连掷两次,以面朝上的数为点P 的坐标(第一次得到的数为横坐标,第二次得到的数为纵坐标),则点P 落在正方形面上(含边界)的概率是( ) A .B .C .D .6.如图,在4×4的正方形方格中,△ABC 的三个顶点在边长为1的小正方形顶点上,则tan ∠ACB 的值为( ) A . B . C . D .3第2题图第6题图第7题图7.如图正方形ABCD 的顶点A 在第二象限xky =图象上,点B ,C 分别在x 轴、y 轴负半轴上,点D 在第一象限直线y =x 的图象上,若32=阴影S ,则k 的值为( )A .34- B .﹣1 C . D .﹣28.如图,在 ABCD 中,点E 在CD 边上,AD =DE =EC ,BD 交AE 于点F ,点O 在线段AB 上,以OA 为半径的⊙O 与BD 恰好相切于点F ,并交AB 于点G ,交AD 于点H ,则BGDH的值为( ) A .94 B .21 C .33 D .53二.填空题:(本题共8小题,每小题6分,共48分)9.有理数a ,b ,c 满足)(21222a b ab c b a -++-=++,则a -b -c = . 10.设205012021120201+++=ΛM ,则M1的整数部分是 . 11.已知x >0,y >0,且511=+++yx y x .则x +y 的最大值是 . 12.设关于x 的方程ax ²+(a +2)x +9a =0有两个不等的实根x 1,x 2,且x 1<1<x 2,那么a的取值范围是 . 13.对于每个非零自然数n ,抛物线)1(1)1(122++++-=n n x n n n x y 与x 轴交于点n A ,n B ,以n n B A 表示这两点间的距离,则202020202211B A B A B A +++Λ的值为 .14.如图,在△ABC 中,BC =√2,AB =1,以AC 为边作等腰直角三角形ACD (以C 为顶点,B ,D 两点在直线AC 两侧),当∠ABC 变化时,线段BD 的最大值为 .15⊙O ,AB =86,若点E E 作DG ∥BC交⊙O 于点D ,G ,交AC 于点F ,若AE ,DE 都是正整数,则DE = .CB A D第8题图第14题图 第15题图16. 对给定的整数,符号表示{}3,21,中使能被3整除的唯一值,那 么_________________.三.解答题(本题共4小题,共58分)17.(本题12分)已知0142=++a a ,且53312324=++++ama a ma a ,求m 的值.18.(本题12分)如图,在△ABC 中,∠A =120°,K ,L 分别是AB ,AC 上的点,向△ABC 外作正三角形BKP 和CLQ .求证:PQ ≥)(23AC AB +.m ()m ϕ()m m ϕ+201020102010(21)(22)(23)ϕϕϕ-+-+-=19.(本题14分)如图,P A为⊙O的切线,PBC为⊙O的割线,AD⊥OP于点D,证明:AD2=BD•CD.20.(本题16分)在平面直角坐标系中,抛物线y=ax2﹣5ax+4a与x轴交于A、B(A点在B点的左侧)与y轴交于点C.(1)如图1,连结AC,BC,若△ABC的面积为3时,求抛物线的解析式;(2)如图2,点P为第四象限抛物线上一点,连接PC,若∠BCP=2∠ABC时,求点P 的横坐标;(3)如图3,在(2)的条件下,点F在AP上,过点P作PH⊥x轴于H点,点K在PH 的延长线上,AK=KF,∠KAH=∠FKH,PF=﹣4a,连接KB并延长交抛物线于点Q,求PQ的长.2020年八年级创新A 班4月返学考试一、选择题(本题有8小题,每小题6分,共48分,每小题只有一个选项是正确的,不选、多选、错选均不给分)1 2 3 4 5 6 7 8 BDCDABAB二、填空题(本题共8个小题,每小题6分,共48分) 9.-1 10.66 11.4 12.0112<<a -13.2021202014.3 15. 12 16.6 三、解答题(本题共4个小题,共46分.解答需要写出必要的文字说明、演算步骤或证明过程) 17.(本题12分)解:由已知可得a a 412-=+,两边平方整理得24141a a =+.∴12141214)1(3)1(522222224-+=+-+=++++=m m ma a ma a ma a a ma a , 解得,237=m . 18.(本题12分)证明:分别过点B ,C 作∠BAC 平分弦的垂线,垂足分别为D ,E ,过点Q 作QF ⊥BP 于点F. 易得BD=23AB ,CE=23AC 则PQ ≥QF=BD+CE=23AB+AC 即PQ ≥)(23AC AB + 19.(本题14分)证明:连接OA 、OC ,23如图, ∵P A 为⊙O 的切线, ∴OA ⊥P A , ∴∠OAP =90°, ∵AD ⊥OP ,∴∠ADP =∠ADO =90°, ∵∠APO =∠DP A , ∴Rt △P AD ∽Rt △POA ,∴P A :PO =PD :P A ,即P A 2=PD •PO ,同理可得Rt△OAD∽Rt△OP A,则OA2=OD•OP,Rt△P AD∽Rt△AOD,则AD2=PD•DO,∵OA2=OD•OP,OC=OA,∴OC2=OD•OP,即OC:OD=OP:OC,而∠POC=∠COD,∴△POC∽△COD;∵P A为⊙O的切线,PBC为⊙O的割线,∴P A2=PB•PC,∴PB•PC=PD•PO,即PB:PO=PD:PC,而∠BPD=∠OPC,∴△PBD∽△POC,∴△PBD∽△COD,∴PD:CD=BD:OD,即PD•OD=BD•CD,∴AD2=BD•CD.20.(本题16分)解:(1)当y=0时,ax2﹣5ax+4a=0,解得x1=1,x2=4,则A(1,0),B(4,0),∴AB=3,∵△ABC的面积为3,∴•3•OC=3,解得OC=2,则C(0,﹣2),把C(0,﹣2)代入y=ax2﹣5ax+4a得4a=﹣2,解得a=﹣,∴抛物线的解析式为y=﹣x2+x﹣2;(2)过点P作PH⊥x轴于H,作CD⊥PH于点H,如图2,设P(x,ax2﹣5ax+4a),则PD=4a﹣(ax2﹣5ax+4a)=﹣ax2+5ax,∵AB∥CD,∴∠ABC=∠BCD,∵∠BCP=2∠ABC,∴∠PCD=∠ABC,∴Rt△PCD∽Rt△CBO,∴PD:OC=CD:OB,即(﹣ax2+5ax):(﹣4a)=x:4,解得x1=0,x2=6,∴点P的横坐标为6;(3)过点F作FG⊥PK于点G,如图3,∵AK=FK,∴∠KAF=∠KF A,而∠KAF=∠KAH+∠P AH,∠KF A=∠PKF+∠KPF,∵∠KAH=∠FKP,∴∠HAP=∠KP A,∴HA=HP,∴△AHP为等腰直角三角形,∵P(6,10a),∴﹣10a=6﹣1,解得a=﹣,在Rt△PFG中,∵PF=﹣4 a=2 ,∠FPG=45°,∴FG=PG=PF=2,在△AKH和△KFG中,∴△AKH≌△KFG(AAS),∴KH=FG=2,∴K(6,2),设直线KB的解析式为y=mx+n,把K(6,2),B(4,0)代入得,解得∴直线KB的解析式为y=x﹣4,当a=﹣时,抛物线的解析式为y=﹣x2+x﹣2,解方程组,解得或,∴Q(﹣1,﹣5),而P(6,﹣5),∴PQ∥x轴,∴PQ=7.。
温州育英国际实验学校2019-2020学年第二学期八年级创新A班4月月考科学试卷Word版一、选择题1.下列用途不是利用了金属的物理性质的是()A.金刚石用于刀具B.水银用于温度计C.铜用于制导线 D.铝用于烧水壶2.下列事例中,改变物体内能的途径与其他三项不同的是()A. B. C. D.3.现有甲、乙、丙、丁四人,在AB0 血型系统中,四人的血型各不相同。
若用丙的血清给其他三人验血,只有乙、丁二人的红细胞起凝集反应;用丁的血清给其他三人验血,只有乙、丙两人的红细胞发生凝集反应。
则乙的血型是()A.A 型B.B 型 C.AB 型D.O 型4.实验室里的化学试剂都是分类存放的,小科在帮老师整理化学药品时,应将纯碱和哪些试剂放在一起()A.Cu、Ag B.NaCl、KNO3 C.HCl、H2SO4 D.NaOH、Ca(OH)25为除去下列物质中的杂质(括号内是,下列操作方法正确的是()选项物质操作方法A Fe (Fe2O3)加入过量稀盐酸,充分反应后过滤B CaO 粉末(CaCO3 粉末)加足量的水,充分搅拌后过滤C NaOH 溶液(Ca(OH)2 溶液)通入过量CO2 气体,充分反应后过滤D CuSO4 溶液(硫酸)加入过量CuO 粉末,加热,充分反应后过滤6()A.32.4% B.3.79% C.7.3% D.88.75%7.Cu 和Fe 的混合粉末若干克,与足量盐酸反应后,过滤。
将滤渣在空气中充分加热,加热后的质量恰好等于原混合物的质量,则原混合物中铁的质量分数()A.40% B.20% C.50.4%D.80%8.由M g(OH)2 和M gO 组成的混合物,测得其中含镁元素的质量分数为48%。
取该混合物10g,将其投入110g 的稀硫酸中恰好完全反应,所得溶液中溶质的质量分数为()A.12% B.20% C.24% D.30%9.一运动员在进行长跑锻炼时,从他的大腿肌细胞中检测到三种化学物质,其浓度变化如图,图中P、Q、R三曲线依次代表()A.乳酸、C02、02B.02、C02、乳酸C.C02、02、乳酸D .C02、乳酸、0210.人的心脏每跳一次大约输送 8×10-5 米3 的血液,正常人血压(可看作心脏压送血液的压强)的平均值约为1.5×104心脏跳约每分钟 70 次。
浙江省温州市育英国际实验学校【最新】八年级上学期科学开学考试A班检测试卷学校:___________姓名:___________班级:___________考号:___________一、选择题1.下列说法正确的是()A.分子是化学变化中的最小粒子B.原子失去电子后变成阴离子C.不同元素之间的本质区别是核外电子数不同D.在离子中,核电荷数等于质子数2.图为某原子结构模型的示意图,其中a、b、c是构成该原子的三种不同粒子,下列说法不正确的是()A.决定该原子种类的粒子是cB.原子中b与c的数目一定相同C.原子中a与c的数目一定相同D.原子的质量集中在b和c上3.最新科技报道,夏威夷联合天文中心的科学家在宇宙深处发现H3+离子和H3分子,以下关于它们的说法不正确的是()A.H3+和H3都是构成物质的微粒B.H3是单质C.一个H3+中含有3个电子D.一个H3中含有3个质子4.梧州每年加工人造宝石总量超过60亿粒,被誉赤“世界人工宝石之都”。
其生产的一种与蓝宝石类似的宝石叫祖母绿,与钻石、红宝石、蓝宝石并称为四大珍贵宝石,是绿宝石家族中最珍贵的成员,它的化学式是Be3Al2(SiO3)6,其中铍元素(Be)的化合价为()A.+1 B.+2 C.+3 D.+45.【最新】中国科学家屠呦呦因青蒿素(C15H22O5)和双氢青蒿素(C15H24O5)而荣获了诺贝尔奖。
下列有关说法中不正确的是()A.青蒿素比双氢青蒿素少两个氢原子B.青蒿素和双氢青蒿素都属于化合物C.青蒿素和双氢青蒿素中碳、氧原子个数比都为3:1D.青蒿素氧元素的质量分数比双氢青蒿素中氧元素的质量分数大6.在化学里,数字被赋予了丰富的内涵。
对下列化学用语中数字“2”的说法正确的是()①2H②2NH3③SO2④O2⑤Mg2+⑥2OH−⑦H2OA.表示离子个数的是⑤B.表示离子所带电荷数的是④⑤C.表示分子中原子个数的是③④⑦D.表示分子个数的是①②7.下列各组物质中,前者是化合物,后者是混合物的是()A.矿泉水、水B.氯化钾、石灰水C.氮气、二氧化碳D.氯化钠、二氧化碳8.具有相同原子数和电子数的分子或离子叫等电子体。
2019-2020学年八年级(上)开学数学试卷一.选择题:(每小题3分,共30分,在每小题给出的四个选项中,只有一项符合题要求)1.函数中,自变量x的取值范围是()A.x>2 B.x<2 C.x≠2 D.x≠﹣2《流浪地球》作为第一部中国自己的科幻大片,票房已破46亿元(4600000000),4600000000 2.科学记数法表示为()A.46×108B.4.6×108C.0.46×109D.4.6×1093.关于x的一元二次方程x2+4x+k=0有两个相等的实数根,则k的值为()A.k=4 B.k=﹣4 C.k≥﹣4 D.k≥44.甲,乙,丙,丁四名同学在学校演讲选拔赛的成绩平均数x与方差S2如下表所示:平均数根据表中数据,要从中选一名成绩好又发挥稳定的同学参加市演讲比赛,应该选择()A.甲B.乙C.丙D.丁5.下列运算正确的是()A.=±3 B.|﹣3|=﹣3C.=﹣3 D.=π﹣46.代数式|x﹣1|﹣|x+2|的最大值为a,最小值为b,下列说法正确的是()A.a=3,b=0 B.a=0,b=﹣3C.a=3,b=﹣3 D.a=3,b不存在7.如图,在△ABC中,AB=AC,∠BAC=120°,AC的垂直平分线交AC于点D,交BC于点E,交BA的延长线于点F,若AF=,则BF的长为()A.B.3 C.2 D.48.如图,点A是反比例函数y=在第一象限图象上一点,连接OA,过点AB作∥x轴(点B在点A右侧),连接OB.若∠1=∠2,其点B的坐标是(8,4),则k的值是()A.6 B.8 C.12 D.169.有甲、乙两种糖果,原价分别为每千克a元和b元.根据调查,将两种糖果按甲种糖果x千克与乙种糖果y千克的比例混合,取得了较好的销售效果.现在糖果价格有了调整:甲种糖果单价下降15%,乙种糖果单价上涨20%,但按原比例混合的糖果单价恰好不变,则等于()A.B.C.D.10.如图,在Rt△ABC中,∠ACB=90°,以AB为边向下作正方形ADEB,连结CD,CE.分别记△ACD,△BCE的面积为S1,S2,用S1,S2的代数式表示边AB的长为()A.B.C.D.二.填空能:(本题共8小题,每小题3分,共24分)11.不等式组的解是.12.如图,两个形状为正十边形的纪念币一边重合放置在一起,则∠α=度.13.如图,在△ABC中,已知AB=8,BC=5,点D,E分别为BC,AC的中点,BF平分∠ABC 交DE于点F,则EF的长为.14.如图,在矩形ABCD中,AB=4,BC=5,点E是边CD的中点,将△ADE沿AE折叠后得到△AFE.延长AF交边BC于点G,则CG为.15.点A是函数y=﹣(x<0)图象上的一点,连结AO并延长交函数y=﹣(x>0)的图象于点B,点C是x轴上一点,且AC=AO,则△ABC的面积为.16.若实数a、b满足a2=7﹣3a、b2=7﹣3b,则代数式的值为.17.如图,在平行四边形ABCD中,M、N分别是BC、DC的中点,AM=4,AN=3,且∠MAN =60°,则AB的长是.18.如图,D为等边△ABC中边BC的中点,在边DA的延长线上取一点E,以CE为边、在CE的左下方作等边△CEF,连结AF.若AB=4,AF=,则CF的值为.三.解答能(共5小题,共46分,解答需写出必要的文字说明,演算步骤或证明过程)19.先化简,再求值:,其中a2+a﹣1=0.20.已知x=2+1,求代数式x3﹣2x2﹣7x+2019的值.21.如图,已知正方形ABCD中,AB=4,点E,F在对角线BD上,AE∥CF.(1)求证:△ABE≌△CDF;(2)若∠ABE=2∠BAE,求DF的长.22.如图,一次函数y=kx+b分别交x轴正半轴、y轴正半轴于点A、B,点P在边OA上运动(点P不与点O,A重合),PE⊥AB于点E,点F,P关于直线OE对称,PE:EA=3:4.若EF∥OA,且四边形OPEF的周长为6.(1)求证:四边形OPEF为菱形;(2)求证:OB=BE;(3)求一次函数y=kx+b的表达式.23.将一副三角尺按如图①方式拼接:含30°角的三角尺的长直角边与含45°角的三角尺的斜边恰好重合(在Rt△ABC中,∠ACB=90°,∠BAC=30°;在Rt△ACD中,∠ADC =90°∠DAC=45°)已知AB=2P是AC上的一个动点.(1)当PD=BC时,求∠PDA的度数;(2)如图②,若E是CD的中点,求△DEP周长的最小值;(3)如图③,当DP平分∠ADC时,在△ABC内存在一点Q,使得∠DQC=∠DPC,且CQ =,求PQ的长.。
2019-2020学年温州育英国际实验学校高三英语上学期期末试卷及答案第一部分阅读(共两节,满分40分)第一节(共15小题;每小题2分,满分30分)阅读下列短文,从每题所给的A、B、C、D四个选项中选出最佳选项AStudents, teachers, and local community members are strongly encouraged to register online to receive real-time information of emergency events fromColumbiaUniversity.Text message warnings will only be used in rare cases where ongoing events causean immediate threat or have a significant influence. Possible situations include severe weather conditions, emergency campus closures, crimes in progress that may endanger the community, and major transportation interruptions.Read instructions on how to sign up for emergency notifications(通知).ColumbiastudentsColumbiastudents can easily register for text message notifications. Simply enter Student Services Online, click on "Text Message Enrollment" and add your cellphone number. 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Users will receive confirmation code(密码)on their phone and will need to confirm their account via email.Users can choose not to use the Emergency Text Alert System at any time by texting STOP to 226787, calling 226789 or sending an email tolr27682@.1.Which is a possiblesituation where a text message will be sent?A.The temperature will drop slightly tomorrow.B.The campus will be closed during Christmas.C.The main railway system of the city is interrupted.D.A bank robber is being sentenced in the court of the city.2.Which step comes before the others when teachers register?A.Selecting Campus Alert.B.Entering mobile numbers.C.Clicking "+" under "Phone".D.Selecting "Faculty& Staff".3.How can users stop receiving text messages?A.By sending an email.B.By texting STOP to 226789.C.By managing information online.D.By making a phone call to 226787.BWhat will people die of 100 years from now? If you think that is a simple question,you have not been paying attention to the revolution that is taking place in bio-technology(生物技术). With the help of new medicine,the human body will last a very long time. Death will come mainly from accidents,murder and war. Today’s leading killers,such as heart disease,cancer,and aging itself,will become distant memories.In discussion of technological changes,the Internet gets most of the attention these days. But the change in medicine can be the real technological event of our times. How long can humans live? Human brains were known to decide the final death. Cells(细胞)are the basic units of all living things,and until recently,scientists were sure that the life of cells could not go much beyond 120 years because the basic materials of cells,such as those of brain cells,would not last forever. But the upper limits will be broken by new medicine. Sometime between 2050 and 2100,medicine will have advanced to the point at which every 10 years or so,people will beable to take medicine to repair their organs(器官). The medicine,made up of the basic building materials of life,will build new brain cells,heart cells,and so on-in much the same way our bodies make new skin cells to take the place of old ones.It is exciting to imagine that the advance in technology may be changing the most basic condition of humanexistence,but many technical problems still must be cleared up on the way to this wonderful future.4. According to the passage,human death is now mainly caused by ________.A. diseases and agingB. accidents and warC. accidents and agingD. heart disease and war5. In the author’s opinion,today’s most important advance in technology lies in(在于)________.A. the InternetB. medicineC. brain cellsD. human organs6. Humans may live longer in the future because ________.A. heart disease will be far away from usB. human brains can decide the final deathC. the basic materials of cells will last foreverD. human organs can be repaired by new medicine7. How long can humans live in the future according to the passage?A. Over 100 years.B. More than 120 years.C. About 150 years.D. The passage doesn’t tell us.CAmerican football was the fastest-growing sport for US young players last year, according to a survey sponsored by the sport's governing body.But it was the game's no tackle variety that showed the biggest increase-a finding that may reflect concerns about injury. In American football, a tackle (抢断球) refers to an attempt to stop an opponent by forcing them to the ground.The number of participants in football grew in 2015 while most other sport, except baseball, posted a decline, USA Football said on Monday, citing(引用) the findings of a survey of 30,000 children and teenagers.Participation in flag football (a no-tackle type of football) increased by 8.7 percent among children aged 6 to 14, while tackle football rose by 1.9 percent. For that age group, the only other sport that grew was baseball, with a 3. 3 percent increase.In the 15-to-18 age group, flag football rose by 10. 5 percent, while tackle grew by 2.5 percent.Basketball was the third, with a 1. 1 percent increase. Participation in all other sports declined.Tom Farrey, executive director of the Aspen Institute's Sports & Society Program, said he was surprised that flag football participation rose so much.“The trend suggests that parents aremarching to the beat of a different drummer, in pursuing flagas an alternative for their kids," he said.The findings come at a time of increasing concern about the risk associated with youth sports, particularly hockey (曲棍球) and football, where medical researchers have warned about the risk of concussions (damagesto the brain caused by violent blows to the head) and death linked to brain injury.USA Football, anIndianapolis,Indianabased nonprofit funded in part by the National Football League, believed that the increases resulted from better safety and health education."Football participation increases, even modest increases, may signal that programs such as our Heads Up Football program and practice guidelines are making a positive difference," said Scot Hallenbeck, USA Football chief executive, in a statement.Robert Cantu, aBostonUniversityneurosurgery professor and investigator at the school's chronic Traumatic Encephalopathy (CTE) Center said the increase in fag football participation signaled that more parents were directing children to a safe alternative8. What can we learn about the two age groups?A. Flag football grew the fastest in the 6-to-18 group.B. Tackle football grew he fastest in the 6-to-14 group.C. Participation in baseball declined the most in both groupsD. Participation in tackle football increased the most in both groups.9. The underlined part probably means ________.A working at a different paceB. behaving in a different wayC. ignoring the major differencesD. trying to accept different opinions10. The popularity of flag football is inked with the fact thatA. its rules have been adapted for young playersB. it receives more funds than other varietiesC. tackle football is an old-fashioned gameD. experts worry about children's safety11. What is the cause of football growth according to USA Football?A. Their safety programs are successful.B. More children show interest in the game.C. Football is less likely to cause concussions.D. There are different types of football to choose from.DSince I was born and brought up in a rural town, I have a great interest in nature. Using the chance of studying abroad in my second year at college, I decided to go toCanadajust because I wanted to see the beautiful phenomena there So after I finished the study program, I went toYellowknifein theNorthwest Territories.I clearly remember the sixth night inYellowknife. Suddenly my host mother came to my room around 8 p.m. and told me to change clothes and go outside quickly carrying her camera.The northern lights were flickering (闪烁) in the sky! I was shocked and just stood there with my mouth open.I forgot to take pictures of the mysterious lights.Since that night, whenever it was sunny, I went outside at night and looked at the sky. It was so cold that I lost all feeling in myhands and feet.As I took pictures of the northern lights, I came to find a characteristic movement of the lights. They first appear in the north part of the sky and then they gradually come down to the south part of the sky. After that, suddenly, they come in the middle of the north and south only for a while, which is the time when the best northern lights can be seen. Since it is only a few seconds for the northern lights to come down to the middle of the sky, it is very hard to get good pictures.The stronger the sun acts, the better and stronger the northern lights flicker in the sky. That’s because they come about from the collisions (碰撞) between atmospheric gases and the solar wind. Much more solar wind comes to the earth when the sun is active, whichleads to the best northern lights. And the color1 s of the northern lights depend on the height of the collisions and the kinds of gases.12. Why did the host mother ask the author to go out?A. She wanted to take a picture of him.B. She wanted to take a walk with him.C. She wanted to tell him something important.D. She wanted him to see the northern lights.13. The author forgot to take pictures after going out because ______.A. the host mother didn’t remind him to take the cameraB. he was shocked by the wonderful sightC. the lights flickering in the sky disappeared too soonD. he lost all feeling in his hands and feet14. When is the best time to see the northern lights?A. When they appear in the north part of the sky.B. When they come down to the south part of the sky.C. When they are between the north and south.D. When they rise in the east part of the sky.15. What does the last paragraph mainly tell us?A. Waysto take good pictures.B. The relationship between the sun and the northern lights.C.The color1 s of the northern lights.D. The time of the best northern lights.第二节(共5小题;每小题2分,满分10分)阅读下面短文,从短文后的选项中选出可以填入空白处的最佳选项。
温州育英国际实验学校八年级上学期科学检测试卷温馨提示:请仔细审题,细心答题,相信你一定会有出色的表现!试卷说明:本试卷总分100分,完卷时间90分钟。
2005-12-15一、选择题:(共40分)1. 为了提醒广大公民注意节约用水,我国制定了“节水徽记”。
“节水徽记”的图案是()2、下列属于溶液的是()A.碘酒B.牛奶C.血液D.纯酒精3. 吃火锅时,我们虽然没往锅内继续放盐,但汤越吃越咸,这是因为()A. 汤的上部淡下部咸B. 汤内盐的质量分数随着水份的蒸发而增大C. 汤内锅底的盐没溶解D. 其它原因4.根据水在通直流电的条件下所发生的变化事实,下列说法正确的是…()A.水是不纯净的B.水是由氢和氧组成的C.水中包含着氢气和氧气D.负极产生了10毫升氢气,正极产生20毫升氧气5、温州市气候属于()A.温带季风性气候B.热带季风性气候C.温带大陆性气候D.亚热带季风性气候6、奥运会射箭运动员在每次经过奥运村的国旗时,都会抬头注视一会儿,其中有一个原因是判断风向,当她看到五星红旗往西飘动时,这时风向为()A、东风B、南风C、西风D、北风7.下列四个事例中,用于增大压强的是()A . 推土机上安装两条履带 B. 铁轨铺在枕木上C. 用滑雪板滑雪D. 把刀刃磨薄8.下面所列举的现象:(1)按在墙上的图钉;(2)吸住在墙上的塑料衣钩;(3)用塑料管从开口的汽水瓶中吸上汽水;(4)气球正在上升。
能说明大气压的存在的是()A.(1)和(2)B. (2)和(3)C.(1)(2)和(3)D.(2)(3)和(4)9.下图中的四个图为滑动变阻器连入电路的几种情况,当滑片P向左移动时,使连入电路中的电阻变大的是()10.如图所示,电源电压保持不变,闭合开关S时出现的情况是()A 、灯L1变亮,电压表示数不变,电流表示数变大B 、灯L1不发光,电压表示数不变,电流表示数变大C 、灯L2变暗,电压表示数变小,电流表示数变小D 、灯L2不发光,电压表示数变大,电流表示数变小11、哈勃望远镜外面穿了一件银白色的外衣,其原因是它所处的高度()A.空气稀薄,温度低,太阳辐射强B.空气稀薄,温度高,太阳辐射强C.空气密度大,温度低,太阳辐射弱D.空气密度大,温度高,太阳辐射弱12、如图所示电路中,属于串联电路的是()A B C D13、在如图所示的电路中,闭合开关S,电压表所测出的电压是()A.电源两极的电压B.R1两端的电压C.R2两端的电压D.R1、R2的总电压14、在制药时,为了从溶液中提取抗菌素,要用加热的方法使水沸腾而除去水分,但抗菌素不能在超过80℃的温度下提取,应采用的方法是()A.增加容器内的气压,使水的沸点低于80℃B.降低容器内的气压,使水的沸点低于80℃C.缩短加热沸腾的时间D.用小火加热15、如图所示的电路中,闭合开关S,当滑动变阻器的滑片P向左移动时,灯L的亮度变化是()A.不变B.变亮C.变暗D.都有可能16、下列关于水的说法中,不正确的是()A、水处在不断的循环运动之中 B 、水是最常见的溶剂C、健康的成年人每天需2.5升的水D、沙漠中的骆驼不需要水材料编号长度(米) 横截面积(毫米2) 材料编号长度(米) 横截面积(毫米2)镍铬① 1 0.5 铜⑤ 1 0.5② 1 1 铜⑥ 1 1L1L2L1 L2L2L1L2L1第15题AVR1R2第17题合金③ 1.5 0.5 铜⑦ 1.5 0.5④ 1.5 1 铁⑧ 1.5 1其中对导体选择最合适的一组是()A.③④⑤⑥B.②③⑥⑦C.⑤⑥⑦⑧D.①⑤⑥⑦18.下列各现象中,不能用液体(气体)流速与压强关系解释的是()A、火车站台上,画有一条白线B、同向行驶的两船不能靠得太近C、飞机起飞时,乘客的耳膜易发生疼痛现象D、在硬币的上方吹气,硬币有可能上跳19.如图所示,盛水容器里浸有四个体积相等的物体半圆形的是石子,三角形的是木块,长方形的是铜块,球形的是铁块,它们受到的浮力分别是F1、F2、F3、F4,试比较它们所受浮力的大小是()A F4>F3>F1>F2B F4 >F1>F3>F2C F1=F2=F3=F4D F1=F3=F4>F220、一个长方形物体A静止在水平桌面上,其右侧正好与桌面对齐,如把物体A向右拉出一些,仍静止在水平桌面上,如右图所示,则物体A对桌面的压力和压强与原来相比()A、压力和压强都改变B、压力改变,压强不变C、压力不变,压强改变D、压力和压强都不变21、下列说法正确的是()A 大气分层的重要依据是气压的垂直变化B、对流层在两极的厚度最薄C、如果没有大气,火山爆发仍然存在D、受对流的影响,热的地方空气垂直运动呈下降22.购买的纸盒包装饮料(如伊犁酸奶等),一般都配有一根饮料吸管(如图所示)正确的使用方法是将尖的一端插入饮料管孔,其目的是………………… [ ]A.减小压强 B.增大压强C.增大压力 D.减小摩擦23.江河堤坝对于防止水土流失,保护两岸居民和行人安全有着十分重要的作用。
2019-2020学年温州育英国际实验学校高三英语上学期期末考试试题及参考答案第一部分阅读(共两节,满分40分)第一节(共15小题;每小题2分,满分30分)阅读下列短文,从每题所给的A、B、C、D四个选项中选出最佳选项AAshish, the 48-year-old surgeon encourages others to do the same through Bloodline, a nonprofit association he founded in 2017. Besides this, he donates blood regularly.According to Ashish, who has been a doctor at a United Family Healthcare hospital in Shanghai since 2007, Bloodline is aimed at creating a blood bank that can help the community as well as individuals with rare blood types who face an urgent need for blood.“My father, a doctor who specialized in treating chest infections, only charged those who could afford the medical treatment. For those who couldn’t pay, he never mentioned money and instead gave them the drugs for free.” he says.During his growing up years, Ashish was also exposed to social services, helping collect food and money for a local children’s hospital.Ashish first donated blood when he was 18. After arriving in China in 2003, Ashish learned mandarin at Fudan University in Shanghai before becoming a graduate student in general surgery at Shanghai Huashan Hospital. Here, he continued participating in blood donation drives as his way of giving back to society. In 2011, he became a volunteer at the Shanghai Blood Center where he helped raise public awareness about blood donations.The idea of setting up an online community for this cause came in 2013 as he believed that there should be a group of expats who get together voluntarily to work with patients and organize regular gatherings to raise public awareness. In 2017, this community was officially registered as Bloodline.“Our organization currently has a presence in 14 cities, including Beijing, Dalian, and Guangzhou. It’s often a small group of people in each city but they can help a great deal.” says Ashish, who holds the roles of ambassador and director of the foreign volunteers group at the Shanghai Blood Center.Ashish has also emphasize the importance of raising awareness of their causes in children, noting that people from the younger generations are more receptive to the idea of donating blood. Bloodline is currently planning to launch a junior club within the organization where youth will get to tour blood donation centers, witness how the blood is dealt, who the end users are, and the difference that they can make to the lives of those in need of blood.“We come from different countries and have different skin color1 s, but the blood streaming through our bodies is the same. When there is a need to roll up sleeves and save lives, we will step forward bravely.” he says.1. The goal of Bloodline is to ________.A. set up a blood bank that can help the communityB. raise money for the charityC. assist children in local hospitalsD. help poor people reduce their financial burden2. What can we infer about Ashish through the whole passage? He ________.A. benefited from blood donation himselfB. got his medical degree in FuDan UniversityC. got the idea of founding Bloodline from his fatherD. helped collect food and money for a local children’s hospital3. What message does the passage convey to us?A. Giving is receivingB. Hard work leads to success.C. One needs to return the favor.D. Love is without boundaries.BThere are 8.8 million blind people in India. In fact, there are 36 million blind people worldwide and a quarter of them are in India; however, many cases of blindness in India are curable. The poor in India have limited access to primary eye healthcare and often do not eat foods rich in micronutrients, like vitamins and minerals, which play an important role in maintaining good eye health.Many people worldwide are not even aware that they may have a vision (视力) problem simply because they do not get their eyes tested every year with a doctor, who tests for the functioning of the eye muscles (肌肉), as well as common diseases like night blindness. This exam is strongly recommended by experts because some changes in vision, which the patient may take longer to notice, can be found easily in this way.Certain simple changes in diet and lifestyle can ensure better eye health for you. These include drinking plenty-of water, not smoking, and eating brightly color1 ed and leafy fruit and vegetables. Wearing sunglasses protects your eyes from the sun, which damages otherwise healthy eyes. Learn about your family's eye disease history, and be on the lookout for any problem about your vision. Make sure that you see a doctor immediately for early intervention(干预) if you see any of these signs of worsening eye health.If you or a loved one needs to cure blindness or other eye diseases, turn to a crowdfunding (众筹) platform. Agroup of eye health caregivers have fundraised with crowdfunding platform ImpactGuru to raise money to perform operations on the eyes of blind women in south Asia. Running an online fundraiser enables both doctors and patients to find a way out of the dark. If you want eye care to develop, start a fundraiser today.4. Why are there so many blind people in India?A. There is a lack of eye hospitals in India.B. People pay no attention to their eyes at all.C. Poor Indians lack food good for eye health.D. The environment damages their eyes.5. What does the author suggest in Paragraph 2?A. Examining your eyes annually.B. Strengthening muscles every day.C. Raising the awareness of physical health.D. Attaching importance to self-examination.6. Which of the following may do harm to your eyes?A. Smoking a lot.B. Wearing sunglasses.C. Drinking much water.D. Watching brightly-color1 ed pictures.7. What does the author want to show in the last paragraph?A. How to start a fundraiser online.B. The importance of raising money.C. The role of crowdfunding in eye care.D. What should bedone to raise money.CLife in the Internet age is lonely—or is it? That’s what experts in human interaction are debating after a new Stanford University survey has been published.According to the study, the more time people spend online, the less they can spare for real-life relationships with family and friends. The researchers asked 113 people about the Web’s influence on daily activities. 36%of those people are online for more than five hours a week.” As Internet use becomes more widespread, it will have an increasingly isolating (孤立的) effect on society,” says Robert Kraut, one of the researchers.Scholars and Web lovers criticized the study for stretching its data to make the “isolating” point. While 13%of regular Web users admitted the loss of time with loved ones, 60%reported watching less TV. The survey alsoshows that E-mail is the most popular online activity. If some of webheads (网虫)spend what was once passive TV time keeping company with friends via E-mails, “that’s a move toward greater connectedness,” says Paul Resnick, a professor at the University of Michigan.Thisisn’t the first claim that the Web should be criticized. A 1998 report monitored 73 Pittsburgh-area families’ Net use for a year. People who used the Internet more “talked less to family members and reported being lonelier and more depressed.” says Robert Kraut.“It’s true that there have been big declines in social connectedness over the past decades, but those declines began before the Internet was invented,” says Thomas Putnam.As Amitay Etzioni says, the Internet gives us a different kind of social life—not better or worse than before, but just different.8. Who claimed that the Web had negative influence?A. Paul Resnick.B. Robert Kraut.C. Thomas Putnam.D. Amitay Etzioni.9. The underlined word “This” in Para.4 refers to .A. the opinion expressed in Bowling AloneB. the survey made by the University of MichiganC. the conclusion in a report written in 1998D. the study conducted by Stanford University10. From the passage we learn that .A. watching TV used to take time away from staying onlineB. the Web was blamed more than once for causing an isolating effectC. 36%ofweb users spend more than five hours a week onlineD. the Web has the same influence as telephones and televisions11. The passage mainly discusses .A. how we can make a better use of the InternetB. how declines in social connectedness appearC. whether the Internet causes an isolating effectD. what a different life the Internet brings to usDWho is a genius? This question has greatly interested humankind for centuries.Let's state clearly: Einstein was a genius. His face is almost the international symbol for genius. But we want to go beyond one man and explore the nature of genius itself. Why is it that some people are so much more intelligent or creative than the rest of us? And who are they?In the sciences and arts, those praised as geniuses were most often white men, of European origin. Perhaps this is not a surprise. It's said that history is written by the victors, and those victors set the standards for admission to the genius club. When contributions were made by geniuses outside the club—women, or people of a different color1 or belief—they were unacknowledged and rejected by others.A study recently published bySciencefound that as young as age six, girls are less likely than boys to say that members of their gender(性别)are “really, really smart.” Even worse, the study found thatgirls act on that belief: Around age six they start to avoid activities said to be for children who are “really, really smart.” Can our planet afford to have any great thinkers become discouraged and give up? It doesn't take a genius to know the answer: ly not.Here's the good news. In a wired world with constant global communication, we're all positioned to see flashes of genius wherever they appear. And the more we look, the more we will see that social factors(因素)like gender, race, and class do not determine the appearance of genius. As a writer says, future geniuses come from those with “intelligence, creativity, perseverance(毅力), and simple good fortune, who are able to change the world.”12. What does the author think of victors' standards for joining the genius club?A. They're unfair.B. They're conservative.C. They're objective.D. They're strict.13. What can we infer about girls from the study inScience?A. They think themselves smart.B. They look up to great thinkers.C. They see gender differences earlier than boys.D. They are likely to be influenced by social beliefs14. Why are more geniuses known to the public?A. Improved global communication.B. Less discrimination against women.C. Acceptance of victors' concepts.D. Changes in people's social positions.15. What is the best title for the text?A. Geniuses Think AlikeB. Genius Takes Many FormsC. Genius and IntelligenceD. Genius and Luck第二节(共5小题;每小题2分,满分10分)阅读下面短文,从短文后的选项中选出可以填入空白处的最佳选项。
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_________________学校_________________班级___________________姓名___________________考号_________________
八年级(上)A 班数学 本卷说明:
①满分 100分,考试时间90分钟.
②答题用蓝(黑)钢(圆珠)笔,并将答案写在答题卷上;画图用铅笔. ③学生不得使用计算器,解答题要有相应计算过程,只有结果不给分.
一.选择题:(每小题 3分,共 30分,在每小题给出的四个选项中,只有一项符合题要求) 1.函数y =1
2x -中,自变量x 的取值范围是( ▲ ) A .x >2B .x <2C .x ≠-2D .x ≠2 2.《流浪地球》作为第一部中国自己的科幻大片,票房已破46亿元(4600000000元), 4 600000000用科学计数法表示为( ▲ ) A.46⨯108B.4.6⨯108C.0.46⨯109D.4.6⨯109
3.关于x 的一元二次方程x 2+4x +k =0有两个相等的实数根,
则k 的值为( ▲ ) A.k =-4 B.k =4 C.k =-14D.k =1
4 4.甲,乙,丙,丁四名同学在学校演讲选拔赛的成绩平均数x 与方差s 2如下表所示: 根据表中数据,要从中选一名成绩好又发挥稳定的同学参加市演讲比赛,应该选择( ▲ ) A .甲 B .乙 C .丙 D .丁 5.下列运算正确的是( ▲ )
A.
3B.33-=-
=-3
π-4 6.代数式12x x --+的最大值为a ,最小值为b ,下列说法正确的是( ▲ ) A.a =3,b =0B.a =0,b =-3C.a =3,b =-3D.a =3,b 不存在 7. 如图,在△ABC 中,AB =AC ,∠
BAC =120°,AC 的垂直平分线交AC 于点D ,交BC 于点E , 交BA 的延长线于点F ,若AF =
BF 的长为( ▲ ) A.
B.3
C.
2 D.4 8.如图,
点A 是反比例函数y =k
x 在第一象限图象上一点,连接OA ,过点A 作AB ∥x 轴(点 B 在点A 右侧)
,连接OB ,若∠1=∠2,且点B 的坐标是(8,4),则k 的值是( ▲ ) A.6 B .8 C.12 D.16 9.有甲、乙两种糖果,原价分别为每千克a 元和b 元,根据调查,将两种糖果按甲种糖果x 千克与乙种糖果y 千克的比例混合,取得了较好的销售效果.现在糖果价格有了调整:甲 种糖果单价下降15%,乙种糖果单价上涨20%,但按原比例混合的糖果单价恰好不变, 则x
y 等于( ▲ )
A.34a b
B.43a b
C.34b a D 43b
a
10.如图,在Rt △ABC 中,∠ACB =90°,以AB 为边向下作正方形ADEB ,连结CD ,CE .分别 记△ACD ,△BCE 的面积为S 1,S 2,用S 1,S 2的代数式表示边AB 的长为( ▲ )
二.填空能:(本题共8小题,每小题3分,共24分)
11. 不等式组32132
x x
x ->⎧⎪
⎨≤⎪⎩的解是 ▲ .
12.如图,两个形状为正十边形的纪念币一边重合放置在一起,则∠α= ▲ 度.
13. 如图,在△ABC 中,已知AB=8,BC=5,点D,E 分别为BC ,AC 的中点,BF 平分∠ABC 交DE 于点F ,则EF 的长为 ▲ .
α
(12题图) (13题图) (14题图) (15题图)
14.如图,在矩形ABCD 中,AB=4,BC=5,点E 是边CD 的中点,将△ADE 沿AE 折叠后得 到△AFE,延长AF 交边BC 于点G ,则CG= ▲ . 15.如图,点A 是函数y =-
8x (x <0)图象上的一点,连结AO 并延长交函数y =-2
x
(x >0) 的图象于点B,点C 是x 轴上一点,且AC=AO,则△ABC 的面积为 ▲ . 16.数a 、b 满足等式a 2 =7-3a ,b 2 =7-3b ,则
b a
a b
+=▲. 17.如图,在平行四边形ABCD 中,M 、N 分别是BC 、DC 的中点,AM =4,AN =3,且 ∠MAN =60︒,则AB 的长是 ▲.
(17题图) (18题图)
18.如图,D 为等边△ABC 中边BC 的中点,在边DA 的延长线上取一点E ,以CE 为边、 在CE 的左下方作等边△CEF ,连结AF 若AB=4,AF=
CF 的值为▲.
三.解答能(共5小题,共46分,解答需写出必要的文字说明,演算步骤或证明过程)
19.(本题8分)先化简,再求值:2221()()121a a
a a a a +-÷--+,其中a 2+a -1=0.
20.(本题6分)已知x=2 +1,求代数式x3-2x2-7x+2019的值.
21.(本题8分)如图,已知正方形ABCD中,AB=4,点E,F在对角线BD上,AE∥CF.(1)求证:△ABE≌△CDF;(2)若∠ABE=2∠BAE,求DF的长.
D
22.(本题12分)如图,一次函数y=kx+b分别交x轴正半轴、y轴正半轴于点A、B,点P 在边OA上运动(点P不与点O,A重合),P E⊥AB于点E,点F,
P关于直线OE对称,P E:EA=3:4.若EF∥OA,且四边形OPEF的周长为6. (1)
求证:四边形OPEF为菱形.
(2)求证:OB=BE.
(3)求一次函数y=kx+b的表达式.
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………………………………………封……………………………………线…………………………………………… 23.(本题12分) 将一副三角尺按如图①方式拼接:含30°角的三角尺的长直角边与含45°
角的三角尺的斜边恰好重合(在Rt △ABC 中,∠ACB =90°,∠BAC =30°;在Rt △ACD 中, ∠ADC =90°∠DAC =45°)已知AB =
P 是AC 上的一个动点. (1)当PD =BC 时,求∠PDA 的度数;
(2)如图②,若E 是CD 的中点,求△DEP 周长的最小值;
(3)如图③,当DP 平分∠ADC 时,在△ABC 内存在一点Q ,使得∠DQC =∠DPC ,且CQ
=2
求PQ 的长.
图①
图②
图③。