人教版初二下册填空题综合
2024年最新人教版初二语文(下册)期末考卷及答案(各版本)
2024年最新人教版初二语文(下册)期末考卷及答案(各版本)(考试时间:90分钟,满分:100分)一、选择题(共10题,每题2分,共20分)1. 下列词语中,加点字的注音完全正确的一项是()。
A. 伫立(zhù)粗犷(guǎng)惬意(qiè)蜷缩(quán)B. 瑰丽(guī)纤维(xiān)憧憬(chōng)矫健(jiǎo)C. 咄咄逼人(duō)草长莺飞(zhǎng)惟妙惟肖(xiào)饮鸩止渴(zhèn)D. 俨然(yǎn)眉宇(yǔ)倔强(jué)矫揉造作(jiǎo)2. 下列句子中没有语病的一项是()。
A. 我们必须加强道德修养,提高文化素质,做一个有益于社会的人。
B. 由于学校加强了对学生健康意识的教育,使学生健康水平有了明显提高。
C. 通过这次活动,使我深刻地认识到团结协作的重要性。
D. 他不仅努力学习,而且取得了优异的成绩,还积极参加体育锻炼。
3. 下列词语中,书写完全正确的一项是()。
A. 偶尔留恋忧郁蕴藏B. 坚韧豪迈勾画勾结C. 沉静告诫侍奉慰藉D. 恳切阴霾羞涩闪烁4. 下列句子中,加点词语运用恰当的一项是()。
A. 他对这个问题一直很感兴趣,一直津津乐道地研究着。
B. 面对困难,他总是泰然处之,毫不气馁。
C. 他对这个问题视而不见,没有给出任何回应。
D. 他对这个问题置之不理,没有给出任何回应。
5. 下列句子中,修辞手法使用恰当的一项是()。
A. 他的眼睛像星星一样闪烁,照亮了整个房间。
B. 他的笑容像阳光一样温暖,让人感到舒适。
C. 他的声音像流水一样清澈,让人心旷神怡。
D. 他的眼神像刀子一样锐利,让人不寒而栗。
6. 下列句子中,标点符号使用正确的一项是()。
A. 他的成绩很好,老师和同学都很喜欢他。
B. 他的成绩很好,老师和同学都很喜欢他。
C. 他的成绩很好,老师和同学都很喜欢他。
D. 他的成绩很好,老师和同学都很喜欢他。
人教版数学八年级下册第16章二次根式混合运算 综合测试卷(含答案)
人教版数学八年级下册第16章二次根式混合运算综合测试卷(含答案)一、填空题(本关共计 12小题,每题 3 分,共计36分)1. 若√2=a,√10=b,则√20用含a,b的式子表示是( )A.2aB.2bC.a+bD.ab2. 下列二次根式中,是最简二次根式的是()A.√20B.√13C.√27D.√123. 下列计算正确的是()A.3√2×4√2=12√2B.√(−9)×(−25)=√9×√−25=(−3)×(−5)=15C.−3√23=√(−3)2×23=6D.√132−122=√(13+12)(13−12)=54. 若m<0,n>0,把代数式m√n中的m移进根号内结果是()A.√m2nB.√−m2nC.−√m2nD.|√m2n|5. 计算:√2x⋅√12xy=()A.√xyB.x√yC.2x√yD.4x√y6. 若a,b为实数,且b=√a2−1+√1−a2a+7+4,则a+b的值为()A.±1B.4C.3或5D.57. 下列计算:①(√2)2=2;②√(−2)2=2;③(−2√3)2=12;④(√2+√3)(√2−√3)=−1.其中正确的有()A.1个B.2个C.3个D.4个8. 下列计算正确的是()A.√20=2√10B.√4−√2=√2C.√2×√3=√6D.√(−2)2=−29. 估计(2√30−√24)⋅√16的值应在()A.1和2之间B.2和3之间C.3和4之间D.4和5之间10. 下列四个运算中,只有一个是正确的.这个正确运算的序号是()①30+3−1=−3;②√5−√2=√3;③(2a2)3=8a5;④−a8÷a4=−a4.A.①B.②C.③D.④11. 与√5可以合并的二次根式是( )A.√10B.√15C.√20D.√2512. 若a=2−√7,则代数式a2−4a−2的值是()A.9B.7C.√7D.1二、填空题(本关共计 6 小题,每题 3 分,共计18分)×√2=________.13. 计算:√9214. √12×√3=________.)×√3=________.15. 计算:(√12+√1316. 计算(√3+1)(√3−1)的结果等于________.17. 如果最简二次根式a√1+a与√4a−2是同类二次根式,那么a=________.=________.18. 已知:m+n=10,mn=9,则√m−√n√m+√n三、解答题(本关共计49分))−219. (5分) 算一算:√6×(−√2)+|1−√3|+(−13220. (15分)计算:(1)√27−13√18−√12;(2)(√20+√5+5)÷√5−√13×√24−√5;(3)√18−√92−√3+√6√3(√3−2)0+√(1−√2)2.21. (10分)计算:(1)(√48−√27)÷√3;(2)(√5−√3)(√5+√3)−(√2+√6)2.22. (10分)计算:(1)12√24−√3×2√2;(2)√32−4√18+√6×√23.23. (6分)已知实数x满足|1−x|−√x2−8x+16=2x−5,求x的取值范围.24.(10分)比一比看谁细心哟!(1)43−(√48÷√64)+√27(2)3√90+√25−4√14025.(10分)已知a=2+√3,b=2−√3,求(1)ab −ba;(2)a2−ab+b24参考答案1.D2.B3.D4.C5.B6.C7.D 8.C 9.B 10. D 11.C 12.D 13.3 14. 6 15.7 16. 2 17.1 18. ±12 19.【答案】原式=−2√3+√3−1+9=8−√3.20.【答案】解:(1)√27−13√18−√12=√3×9−13√2×9−√4×3 =3√3−√2−2√3=√3−√2.(2)(√20+√5+5)÷√5−√13×√24−√5 =√20÷√5+√5÷√5+5÷√5−√33×2√6−√5 =2+1+√5−2√2−√5=3−2√2.(3)√18−√92√3√6√3+(√3−2)0+√(1−√2)2 =3√2−3√22−(1+√2)+1+√2−1 =3√22−1.21.【答案】解:(1)原式=(4√3−3√3)÷√3=√3÷√3=1.(2)原式=5−3−(8+4√3)6 =5−3−8−4√3 =−6−4√3.22.【答案】解:(1)12√24−√3×2√2 =√6−2√6=−√6. (2)√32−4√1+√6×√2=4√2−√2+2=3√2+2.23.【答案】解:|1−x|−√x 2−8x +16 =|1−x|−|x −4| =x −1+x −4=2x −5,即1−x ≤0且x −4≤0, ∴ 1≤x ≤4,即x 的取值范围是1≤x ≤4. 24.【答案】原式=43−4√48×16+3√3 =43−8√2+3√3; 原式=9√10+√105−√105=9√10.25.【答案】当a =2+√3,b =2−√3时,原式=√32−√3√3 2+√3=(2+√3)2(2+√3)(2−√3)(2−√3)2(2+√3)(2−√3)=7+4√34−3−7−4√34−3=7+4√3−7+4√3=8√3;当a=2+√3,b=2−√3时,原式=(a+b)2−3ab=(2+√3+2−√3)2−3×(2+√3)(2−√3)=16−3×(4−3)=16−3=13.。
人教版 八年级下 期末专题复习(综合填空)含答案
人教版八年级下期末专题复习综合填空一、阅读下面短文,在空白处按要求填入适当的单词或括号内单词的正确形式。
Most children like watching TV. It's very ___1___ (interest). By watching TV, they can see and learn a lot and know many things about ___2___ (they) country and the world. Of course, they can also learn over the radio. They can learn something more ___3___ (quick) from those TV ___4___ (program) because they can hear and watch at ___5___ same time. But they can't see anything over the radio. TV ___6___ (help) to open children's eyes and minds. Many children watch TV only on Saturday or Sunday evening, ___7___ they often have a lot of homework to do. But if they spend more time ___8___ (watch) TV, they will have ___9___ (little) time to do their lessons and fall ___10___ other students. So when you want to watch TV, you must remember, “Study must come first.”二、阅读下面短文,在空白处按要求填入适当的单词或括号内单词的正确形式。
人教版八年级下册物理综合试卷
人教版八年级下册物理综合试卷一、选择题(每题3分,共30分)1. 下列物体的重力最接近1N的是()A. 一只老母鸡。
B. 一片树叶。
C. 一包方便面。
D. 一袋大米。
2. 关于力的概念,下列说法中正确的是()A. 力可以离开物体而单独存在。
B. 两个物体只要相互接触,就一定有力的作用。
C. 两个不相互接触的物体之间,一定没有力的作用。
D. 有力的作用就一定有施力物体和受力物体。
3. 如图所示的四个实例中,属于增大压强的是()A. 滑雪板的面积较大。
B. 书包的背带较宽。
C. 刀刃磨得很薄。
D. 坦克的履带很宽。
4. 下列现象中,不属于惯性现象应用的是()A. 用手拍打衣服上的灰尘。
B. 运动员采用助跑跳远。
C. 锤头松了,将锤柄在地上撞击几下。
D. 骑自行车时为了减速捏刹车闸。
5. 一物体在水平面上做圆周运动,假设它所受外力同时消失,则物体将()A. 做减速直线运动。
B. 做曲线运动。
C. 做匀速直线运动。
D. 做圆周运动。
6. 如图所示,放在水平桌面上的容器A为圆柱形,容器B为圆锥形,两容器本身的质量和底面积都相同,装入深度相同的水后,再分别放入相同质量的木块,下列说法正确的是()A. 放入木块前,两容器对桌面的压力相等。
B. 放入木块前,两容器底部所受水的压力相等。
C. 放入木块后,两容器底部所受水的压力相等。
D. 放入木块后,两容器对桌面的压力相等。
7. 潜水艇在海面下航行时,人们可以用潜望镜观察海面上的情况,潜望镜是利用光的()原理制成的。
A. 直线传播。
B. 反射。
C. 折射。
D. 色散。
8. 一个物体重100N,受到的空气阻力大小为10N,则下列说法中正确的是()A. 若物体竖直向上运动时,合力大小是110N,方向竖直向下。
B. 若物体竖直向上运动时,合力大小是90N,方向竖直向下。
C. 若物体竖直向下运动时,合力大小是110N,方向竖直向下。
D. 若物体竖直向下运动时,合力大小是90N,方向竖直向上。
人教版数学初二年级下册学期综合检测卷三
精品基础教育教学资料,仅供参考,需要可下载使用!人教版数学初二下学期综合检测卷一、单选题(18分)1.(3分)由下列条件不能判定△ABC为直角三角形的是()A.∠A+∠B=∠CB.∠A:∠B:∠C=1:3:2C.(b+c)(b-c)=a2D.a=,b=,c=2.(3分)用配方法将方程x2+6x-11=0变形,正确的是()A.(x-3)2=20B.(x-3)2=2C.(x+3)2=2D.(x+3)2=203.(3分)下列四个命题:①一组对边平行且一组对角相等的四边形是平行四边形;②对角线互相垂直且相等的四边形是正方形;③顺次连接矩形四边中点得到的四边形是菱形;④对角线相等且互相垂直的四边形是菱形,其中真命题共有()A.1个B.2个C.3个D.4个4.(3分)下列各式中,最简二次根式有(),,,,,.A.2个B.3个C.4个D.5个5.(3分)二次函数y=ax2+bx+c的图象如图所示,则一次函数y=bx-ac与反比例函数在同一坐标系内的图象大致为()A.B.C.D.6.(3分)如图,在平行四边形ABCD中,AD=2AB,F是AD的中点,作CE⊥AB,垂足E在线段AB上,连接EF、CF,则下列结论中一定成立的是()①∠DCF=∠BCD;②S△BEC=2S△CEF;③∠DFE=3∠AEF;④当∠AEF=54°时,则∠B=68°.A.①③B.②③④C.①④D.①③④二、填空题(18分)7.(3分)阅读下面材料在数学课上,老师提出如下问题:已知:已知:Rt△ABC,∠ABC=90°.求作:矩形ABCD.小敏的作法如下:①以A为圆心,BC长为半径作弧,以C为圆心,AB长为半径作弧,两弧相交于点D;②连接DA、DC;所以四边形ABCD为所求矩形.老师说:“小敏的作法正确.”请回答:小敏的作法正确的理由是.8.(3分)如图若将左边正方形剪成四块,恰能拼成右边的矩形,设a=1,则这个正方形的面积是.9.(3分)已知直线y=2x+2与x轴、y轴分别交于点A,B.若将直线y=x向上平移n个单位长度与线段AB有公共点,则n的取值范围是.10.(3分)直线y=-x+m与y=x+5的交点的横坐标为-2,则关于x的不等式-x+m>x+5>0的整数解为.11.(3分)沿河岸有A,B,C三个港口,甲、乙两船同时分别从A、B港口出发,匀速驶向C港,最终到达C港.设甲、乙两船行驶x(h)后,与B港的距离分别为y1、y2(km),y1、y2与x的函数关系如图所示.考察下列结论:①乙船的速度是25 km/h;②从A港到C港全程为120 km;③甲船比乙船早1.5小时到达终点;④若设图中两者相遇的交点为P点,P点的坐标为(,);⑤如果两船相距小于10 km能够相互望见,那么甲、乙两船可以相互望见时,x的取值范围是<x<2.其中正确的结论有.12.(3分)如图,在边长为2的菱形ABCD中,∠A=60°,点M是AD边的中点,连接MC,将菱形ABCD翻折,使点A落在线段CM上的点E处,折痕交AB 于点N,则线段EC的长为.三、解答题(84分)13.(6分)已知关于x的一元二次方程x2-mx-2=0.(1)证明:对于任意实数m,方程总有两个不相等的实数根.(2)若方程有一个根为-2,求m的值.14.(6分)解方程:(1)3x(x-1)=2(x-1).(2)x2-6x+6=0.15.(6分)如图,正方形ABCD中,以对角线BD为边作菱形BDFE,使B,C,E三点在同一直线上,连接BF,交CD与点G.(1)求证:CG=CE.(2)若正方形边长为4,求菱形BDFE的面积.16.(6分)等边△OAB在平面直角坐标系中,已知点A(2,0),将△OAB绕点O 顺时针方向旋转a°(0<a<360)得△OA1B1.(1)求出点B的坐标.(2)当A1与B1的纵坐标相同时,求出a的值.(3)在(2)的条件下直接写出点B1的坐标.17.(6分)阅读下面材料:在数学课上,老师提出如下问题:已知:如图,四边形ABCD是平行四边形;求作:菱形AECF,使点E,F分别在BC,AD上.小凯的作法如下:(1)连接AC;(2)作AC的垂直平分线EF分别交BC,AD于E,F.(3)连接AE,CF,所以四边形AECF是菱形.老师说:“小凯的作法正确”.回答下列问题:根据小凯的做法,小明将题目改编为一道证明题,请你帮助小明完成下列步骤:(1)已知:在平行四边形ABCD中,点E、F分别在边BC、AD上,.(补全已知条件)求证:四边形AECF是菱形.(2)求证:四边形AECF是菱形.(写出证明过程)18.(8分)如图是一副秋千架,左图是从正面看,当秋千绳子自然下垂时,踏板离地面0.5 m(踏板厚度忽略不计),右图是从侧面看,当秋千踏板荡起至点B位置时,点B离地面垂直高度BC为1 m,离秋千支柱AD的水平距离BE为1.5 m(不考虑支柱的直径).求秋千支柱AD的高.19.(8分)已知关于x的方程x2-4mx+4m2-9=0.(1)求证:此方程有两个不相等的实数根.(2)设此方程的两个根分别为x1,x2,其中x1<x2.若2x1=x2+1,求m的值.20.(8分)综合与探究问题情境:如图1,在△ABC中,AB=AC,点D,E分别是边AB,AC上的点,且AD=AE,连接DE,易知BD=CE.将△ADE绕点A顺时针旋转角度α(0°<α<360°),连接BD,CE,得到图2.(1)变式探究:如图2,若0°<α<90°,则BD=CE的结论还成立吗?若成立,请证明;若不成立,请说明理由.(2)拓展延伸:若图1中的∠BAC=120°,其余条件不变,请解答下列问题:从A,B两题中任选一题作答我选择____题.A、①在图1中,若AB=10,求BC的长;②如图3,在△ADE绕点A顺时针旋转的过程中,当DE的延长线经过点C时,请直接写出线段AD,BD,CD之间的等量关系.B、①在图1中,试探究BC与AB的数量关系,并说明理由;②在△ADE绕点A顺时针旋转的过程中,当点D,E,C三点在同一条直线上时,请借助备用图探究线段AD,BD,CD之间的等量关系,并直接写出结果.21.(9分)在一次全程为20 km的越野赛中,甲、乙两名选手所跑的路程y(km)与时间x(h)之间函数关系的图象如图中折线O-A-B-C和线段OD所示,两图象的交点为M.根据图中提供的信息,解答下列问题:(1)请求出图中a的值.(2)在乙到达终点之前,问:当x为何值时,甲、乙两人相距2 km?22.(9分)如图,在长方形ABCD中,边AB、BC的长(AB<BC)是方程的两个根.点P从点A出发,以每秒1个单位的速度沿△ABC边A→B→C→A 的方向运动,运动时间为t(秒).(1)求AB与BC的长.(2)当点P运动到边BC上时,试求出使AP长为时运动时间t的值.(3)当点P运动到边AC上时,是否存在点P,使△CDP是等腰三角形?若存在,请求出运动时间t的值;若不存在,请说明理由.23.(12分)如图,在△ABC中,AB=AC=13厘米,BC=10厘米,AD⊥BC于点D,动点P从点A出发以每秒1厘米的速度在线段AD上向终点D运动,设动点运动时间为t秒.(1)求AD的长.(2)当P、C两点的距离为时,求t的值.(3)动点M从点C出发以每秒2厘米的速度在射线CB上运动.点M与点P同时出发,且当点P运动到终点D时,点M也停止运动.是否存在时刻t,使得S△PMD=S△ABC?若存在,请求出t的值;若不存在,请说明理由.答案一、单选题1.【答案】D【解析】A、∵∠A+∠B=∠C,∴∠C=90°,故是直角三角形,正确;B、∵∠A:∠B:∠C=1:3:2,∴∠B=×180°=90°,故是直角三角形,正确;C、∵(b+c)(b-c)=a2,∴b2-c2=a2,即a2+c2=b2,故是直角三角形,正确;D、设a=20k,b=15k,c=12k,∵(12k)2+(15k)2≠(20k)2,故不能判定是直角三角形.故答案为:D.2.【答案】D【解析】把方程x2+6x-11=0的常数项移到等号的右边,得到x2+6x=11,方程两边同时加上一次项系数一半的平方,得到x2+6x+9=11+9,配方得(x+3)2=20.故答案为:D.3.【答案】B【解析】①一组对边平行,且一组对角相等,则可以判定另外一组对边也平行,所以该四边形是平行四边形,故①正确;②对角线互相平分、垂直且相等的四边形是正方形,故②是假命题;③因为矩形的对角线相等,所以连接矩形的中点后都是对角线的中位线,所以四边相等,所以是菱形,故③正确;④对角线互相平分且互相垂直的四边形是菱形,故④是假命题.故答案为:B.4.【答案】B【解析】被开方数含能开得尽方的因数,不是最简二次根式;被开方数含分母,不是最简二次根式;是最简二次根式;是最简二次根式;是最简二次根式;被开方数含能开得尽方的因数,不是最简二次根式.故选B。
八年级数学下册第十六章《分式》单元 填空题 大全 新课标人教版 (4)
八年级数学下册第十六章《分式》单元 填空题 大全 新课标人教版1. 分式,21x xyy 51,212-的最简公分母为________________;2. 下列各式中:x 23,32x ,,231x -πx, 有( )个分式。
3. 轮船顺水航行46km 和逆水航行34km 所用的时间恰好相等,水的流速是3km/h ,设轮船在静水中的速度是xkm/h ,可列得方程为___________________。
4. 用科学记数法表示-0.000000102=_________。
5. 化简(ab —b 2)÷abba -的结果为___________. 6. 若关于x 的方程211=--ax a x 的解是x=2,则a=__________; 7. 要使2415--x x 与的值相等,则x =__________. 8. 分式392--x x 当x _________时分式的值为零,当x ________时,分式xx2121-+有意义. 9. 当x 为_____时,分式1263--x x 的值为0. 10. 为改善生态环境,防止水土流失,某村拟在荒坡地上种植960棵树, 由于青年团员的支持,每日比原计划多种20棵,结果提前4天完成任务,问原计划每天种植多少棵树?设原计划每天种植棵树,根据题意可列方程__________________. 11.若分式22221x x x x --++的值为0,则x 的值等于___.若分式11x x +-的值为0,那么x 的值__.12. 填空:(1)3( )510a xy axy =(2)3233638( )a b a b = (3)2282m n mn =__________ (4)2214( )a a +=-(5)32()x y y x -=-______(6)2221a b b÷⨯=_____ 13. 已知实数a b ,满足:=1ab ,那么221111a b +++的值为_____. 14. 已知31=ba,分式ba ba 52-+的值为___________; 15.若关于x 的方程11ax x +--1=0无实根,则a 的值为_______________. 16. 计算:2211121(1)a a a a a +---+-=___________. 17. 计算:2933a a a -=--_________. 18. 当x =________时,分式2||22x x x ---的值为零.19. 当x=_______时,分式x -51与x 3210-互为相反数.20.当x =________时,分式42322-+-x x x 的值为零; 当x =________时,这个分式无意义.21. 用科学记数法表示—0.000 000 0314=_________________. 22.()221112211x x x +--把分式、、通分,最简公分母是__________________. 23. 函数2y 1x x -=-中自变量x 的取值范围是___________;计算:xx x 11+-=_________24.计算:2933a a a -=--_________. 25. 若21=-y y x ,则y x =___________;26. 已知2+,,15441544,833833,32232222 ⨯=+⨯=+⨯=若10+b a bab a ,(102⨯=为正整数)27.分式392--x x 当x __________时分式的值为零。
人教版八年级物理下册填空题复习试题含答案
人教版八年级物理下册填空题复习试题含答案第七章二、填空题(本大题共10个小题,每小题2分,满分20分)9.如图所示,为某中学足球赛的精彩画面,脚把足球踢飞,说明力可以改变物体的运动状态;同时脚感觉到疼,说明力的作用是相互的。
10.如图甲、乙所示,“跳橡皮筋”和“击打陀螺”是孩子们喜欢玩的游戏,其中图__乙__(选填“甲”或“乙”)主要表示了力可以使物体的运动状态发生改变。
另一图说明力的作用效果是力可以__改变物体的形状__。
11.人踢球时,对球施力的物体是__脚__,同时脚也受到球的作用力,这一事例说明__物体间力的作用是相互的__。
第11题图第12题图12.如图,用水平力轻轻推动矿泉水瓶底部时,瓶子沿着平面稳稳地移动;用等大的水平力轻推瓶盖,瓶子翻了,这说明力的作用效果与力的__作用点__(选填“大小”“方向”或“作用点”)有关,“翻了”说明力可以改变物体的__运动状态__。
13.如图所示,小明用力拉长橡皮筋,将“纸弹”弹出去。
其中,橡皮筋发生了弹性(选填“弹性”或“塑性”)形变,产生的弹力使“纸弹”的运动状态发生改变。
第13题图14.如图所示,用弹簧测力计测一物体所受重力,由图可知,物体所受重力为1.4N,重力的施力物体是地球。
第14题图第15题图15.如图所示,某人用12 N的力沿水平方向向右拉一根轻质弹簧,弹簧对手的拉力等于(选填“大于”“小于”或“等于”)12 N,手受到的拉力的施力物体是弹簧。
16.“人往高处走,水往低处流”是因为水受到__重力__的作用,其方向总是__竖直向下__。
17.(玉林中考)一个桥头立着如图所示的限重标志牌。
这座桥面受到的压力超过__2×105__N时,就可能发生危险。
当汽车行驶在桥面上时,它所受重力的方向是__竖直向下__。
(取g=10 N/kg)第17题图18.小金对太空中的星球比较感兴趣,他从网上查得:甲、乙两个星球表面上物体的重力(G)与其质量(m)的关系如图。
人教版八年级数学下册期末综合素质评价附答案
人教版八年级数学下册期末综合素质评价一、选择题(每题3分,共30分)1.函数y=xx-2的自变量x的取值范围是()A.x≥0且x≠2B.x≥0 C.x≠2D.x>2 2.下列二次根式中,最简二次根式是()A. 2B.12C.15 D.a23.下面各组数中,是勾股数的是()A.9,16,25 B.0.3,0.4,0.5 C.1,3,2 D.7,24,254.在体操比赛评分时,要去掉一个最高分和一个最低分,这样做的目的是() A.使平均数不受极端值的影响B.使众数不受极端值的影响C.使中位数不受极端值的影响D.使方差不受极端值的影响5.【2022·仙桃】下列各式计算正确的是()A.2+3= 5 B.43-33=1C.2×3= 6D.12÷2= 66.如图,平行四边形ABCD中,对角线AC、BD交于点E,点F是CD的中点,若AD=10 cm,则EF的长为()A.3 cm B.4 cm C.5 cm D.6 cm(第6题)(第7题)(第8题)(第9题) 7.赵老师是一名健步走运动的爱好者,她用微信运动记录了某个月(30天)每天健步走的步数(单位:万步),将记录结果绘制成了如图所示的统计图.在每天健步走的步数这组数据中,众数和中位数分别是()A.1.2,1.3 B.1.4,1.3C.1.4,1.35 D.1.3,1.38.【教材P 43练习T 2变式】【2022·赤峰】如图,剪两张对边平行的纸条,随意交叉叠放在一起,重合部分构成一个四边形ABCD ,其中一张纸条在转动过程中,下列结论一定成立的是( )A .四边形ABCD 的周长不变B .AD =CDC .四边形ABCD 的面积不变 D .AD =BC9.【直观想象】如图,一只蚂蚁绕着圆柱向上螺旋式爬行,假设蚂蚁绕圆柱外壁从点A 爬到点B ,圆周率π取近似值3,则蚂蚁爬行路线的最短路径长为( )A .6 2 cmB .6 5 cmC .213 cmD .10 cm10.【新考法题】【2022·安徽】甲、乙、丙、丁四个人步行的路程和所用的时间如图所示,按平均速度计算,走得最快的是( )A .甲B .乙C .丙D .丁二、填空题(每题3分,共24分)11.计算:(-4)2=________.12.【2022·广州】在甲、乙两位射击运动员的10次考核成绩中,两人的考核成绩的平均数相同,方差分别为s 甲2=1.45,s 乙2=0.85,则考核成绩更为稳定的运动员是________(填“甲”“乙”中的一个).13.如图,直线y =x -3与直线y =mx (m ≠0)交于点P ,则关于x ,y 的二元一 次方程组⎩⎨⎧y =x -3,y =mx的解为__________.(第13题) (第15题) (第17题) (第18题)14.【立德树人】【2022·青岛】小明参加“建团百年,我为团旗添光彩”主题演讲比赛,其演讲形象、内容、效果三项得分分别是9分、8分、8分.若将三项得分依次按3:4:3的比例确定最终成绩,则小明的最终比赛成绩为________分.15.【教材P 67复习题T 5改编】【2022·黔东南州】如图,矩形ABCD 的对角线AC ,BD 相交于点O ,DE ∥AC ,CE ∥BD .若AC =10,则四边形OCED 的周长是________.16.已知一次函数y =(k +3)x +k -2,y 随x 的增大而增大,且图象与y 轴交于负半轴,则k 的取值范围是__________.17.【2022·江西】沐沐用七巧板拼了一个对角线长为2的正方形,再用这副七巧板拼成一个长方形(如图所示),则长方形的对角线长为________.18.【教材P 109复习题T 14变式】已知A 地在B 地正南方向3 km 处,甲、乙两人同时分别从A ,B 两地向正北方向匀速直行,他们与A 地的距离s (km)与所行时间t (h)之间的函数关系图象如图中的OC 和FD 所示.当他们行走3 h 后,他们之间的距离为________km.三、解答题(19~21题每题8分,22~24题每题10分,25题12分,共66分)19.计算:(1)()32+48()18-43;(2)(2-3)2 024·(2+3)2 023-2⎪⎪⎪⎪⎪⎪-32-(-2)0.20.已知a ,b ,c 满足|a -7|+b -5+(c -42)2=0.(1)求a,b,c的值;(2)判断以a,b,c为边能否构成三角形,若能构成三角形,此三角形是什么形状?21.【2022·厦门双十中学模拟】如图,已知一次函数y=kx+b的图象经过A(-2,-1),B(1,3)两点,并且交x轴于点C,交y轴于点D.(1)求该一次函数的解析式;(2)求△AOB的面积.22.【2022·达州】“防溺水”是校园安全教育工作的重点之一,某校为确保学生安全,开展了“远离溺水·珍爱生命”的防溺水安全知识竞赛.现从该校七、八年级中各随机抽取10名学生的竞赛成绩(百分制)进行整理和分析(成绩得分用x 表示,共成四组:A.80≤x<85,B.85≤x<90,C.90≤x<95,D.95≤x≤100).下面给出了部分信息:七年级10名学生的竞赛成绩是:96,84,97,85,96,96,96,84,90,96.八年级10名学生的竞赛成绩在C组中的数据是:92,92,94,94.根据以上信息,解答下列问题:(1)上述图表中a=________,b=________,m=________.(2)根据以上数据,你认为该校七、八年级中哪个年级学生掌握防溺水安全知识较好?请说明理由(一条理由即可).(3)该校七、八年级共1 200人参加了此次竞赛活动,估计参加此次竞赛活动成绩优秀(x≥95)的学生人数是多少.23.如图,在矩形ABCD中,点E,F分别在边CD,AB上,且DE=BF,∠ECA=∠FCA.(1)求证:四边形AFCE是菱形;(2)若AB=8,BC=4,求菱形AFCE的面积.24.【2022·衡阳】冰墩墩、雪容融分别是2022年北京冬奥会、冬残奥会的吉祥物.冬奥会来临之际,冰墩墩、雪容融玩偶畅销全国,小雅在某网店选中两种玩偶.决定从该网店进货并销售,第一次小雅用1 400元购进了冰墩墩玩偶15个和雪容融玩偶5个,已知购进1个冰墩墩玩偶和1个雪容融玩偶共需136元,销售时每个冰墩墩玩偶可获利28元,每个雪容融玩偶可获利20元.(1)求两种玩偶的进价分别是多少;(2)第二次小雅进货时,网店规定冰墩墩玩偶进货数量不得超过雪容融玩偶进货数量的1.5倍,小雅计划购进两种玩偶共40个,应如何设计进货方案才能获得最大利润?最大利润是多少元?25.已知四边形ABCD是正方形,点F在边AB,BC上运动,DE⊥DF,且DE =DF,M为EF的中点.(1)当点F在边AB上时(如图①).①求证:点E在直线BC上;②若BF=2,则MC的长为________.(2)当点F在BC上时(如图②),求BFCM的值.答案一、1.A 2.A 3.D 4.A 5.C 6.C 7.B8.D 9.A10.A 提示:∵经过30 min 甲比乙步行的路程多,经过50 min 丁比丙步行的路程多,∴甲的平均速度大于乙的平均速度,丁的平均速度大于丙的平均速度.∵步行3 km 时,甲比丁用的时间少,∴甲的平均速度大于丁的平均速度.∴走得最快的是甲.二、11.4 12.乙13.⎩⎨⎧x =1y =-214.8.3 15.2016.-3<k <2 17. 5点思路:根据图形可得长方形的长等于正方形的对角线长,为2;长方形的宽等于正方形对角线长的一半,为1,然后利用勾股定理即可解决问题.18.1.5三、19.解:(1)原式=(32+43)(32-43)=(32)2-(43)2=18-48=-30;(2)原式=[(2-3)(2+3)]2 023·(2-3)-3-1=2-3-3-1=1-2 3.20.解:(1)∵a ,b ,c 满足|a -7|+b -5+(c -42)2=0,∴|a -7|=0,b -5=0,(c -42)2=0,解得a =7,b =5,c =4 2.(2)∵a =7,b =5,c =42,∴a +b =7+5>4 2.∴以a ,b ,c 为边能构成三角形.∵a 2+b 2=(7)2+52=32=(42)2=c 2,∴此三角形是直角三角形.21.解:(1)把A (-2,-1),B (1,3)两点的坐标分别代入y =kx +b ,得⎩⎨⎧-2k +b =-1,k +b =3,解得⎩⎪⎨⎪⎧k =43,b =53.∴该一次函数的解析式为y =43x +53.(2)把x =0代入y =43x +53,得y =53, ∴点D 的坐标为⎝ ⎛⎭⎪⎫0,53. ∴S △AOB =S △AOD +S △BOD =12×53×2+12×53×1=52.22.解:(1)30;96;93(2)八年级学生掌握防溺水安全知识较好.理由:虽然七、八年级的平均分均为92,但八年级的众数高于七年级.(合理即可)(3)1 200×6+10×30%20=540(人). 答:估计参加此次竞赛活动成绩优秀(x ≥95)的学生人数是540人.23.(1)证明:∵四边形ABCD 是矩形,∴CD ∥AB ,CD =AB .∵DE =BF ,∴EC =AF .又∵EC ∥AF ,∴四边形AFCE 是平行四边形.∵CD ∥AB ,∴∠ECA =∠F AC .∵∠ECA =∠FCA ,∴∠F AC =∠FCA ,∴F A =FC . ∴平行四边形AFCE 是菱形.(2)解:设FB =x ,则AF =CF =8-x .在Rt △BCF 中,42+x 2=(8-x )2,解得x =3.∴菱形的边长AF =8-3=5.∴菱形AFCE 的面积为5×4=20.点要点:矩形与菱形的区别:1.矩形和菱形都是建立在平行四边形的基础上,矩形是附加一直角,而菱形是附加一组邻边相等;2.矩形的两条对角线把矩形分割成四个面积相等的等腰三角形,而菱形的两条对角线把菱形分割成四个全等的直角三角形;3.矩形的对称轴是两条过两组对边中点的直线,而菱形的对称轴是两条对角线所在的直线.24.解:(1)设冰墩墩玩偶的进价为x 元/个,雪容融玩偶的进价为y 元/个.根据题意,得⎩⎨⎧15x +5y =1 400,x +y =136,解得⎩⎨⎧x =72,y =64.答:冰墩墩玩偶的进价为72元/个,雪容融玩偶的进价为64元/个.(2)设冰墩墩玩偶购进a 个,则雪容融玩偶购进(40-a )个,利润为w 元. 根据题意,得w =28a +20(40-a )=8a +800.∵8>0,∴w 随a 的增大而增大.∵网店规定冰墩墩玩偶进货数量不得超过雪容融玩偶进货数量的1.5倍, ∴a ≤1.5(40-a ),解得a ≤24.∴当a =24时,w 取得最大值,此时w =992,40-a =16.答:冰墩墩玩偶购进24个,雪容融玩偶购进16个时,才能获得最大利润,最大利润是992元.25.(1)①证明:如图①,连接CE .∵DE ⊥DF ,∴∠FDE=90°.∵四边形ABCD是正方形,∴∠ADC=∠DAF=∠DCB=90°,DA=DC.∴∠ADC-∠FDC=∠FDE-∠FDC,即∠ADF=∠CDE.又∵DF=DE,∴△DAF≌△DCE(SAS).∴∠DAF=∠DCE=90°.∴∠DCE+∠DCB=180°.∴点E在直线BC上.② 2(2)解:如图②,在DC上截取DN=FC,连接MN,DM,设EF,CD相交于点H.∵△FDE为等腰直角三角形,M为EF的中点,∴DM=12EF=FM,DM⊥EF.∴∠DMF=∠FCD=90°.∴∠CDM+∠DHM=∠MFC+∠CHF.又∵∠DHM=∠CHF,∴∠CDM=∠MFC.∴△DNM≌△FCM(SAS).∴MN=MC,∠DMN=∠FMC.∴∠DMN+∠FMN=∠FMC+∠FMN,即∠DMF=∠NMC=90°.∴△CNM是等腰直角三角形.∴CN=2CM.又∵DC=BC,DN=CF,∴CN=BF.∴BF=2CM,即BFCM= 2.。
人教版八年级下期末复习综合练习题(含答案)
∵E 是▱ABCD 的边 CD 的中点,
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知识像烛光,能照亮一个人,也能照亮无数的人。--培根
∴DE=CE, 在△ADE 和△FCE 中,
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∴△ADE≌△FCE(AAS);
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19.解:(1)∵每个小正方形的边长都是 1,
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8.如图是一个运算程序的示意图,若输出 y 的值为 2,则输入 x 的值可能为( )
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9.《九章算术》是我国古代的数学名著,书中的“折竹抵地”问题:今有竹高一丈,末折
抵地,去本三尺.问折者高几何?意思是:一根竹子,原高一丈(一丈=10 尺),一阵
知识像烛光,能照亮一个人,也能照亮无数的人。--培根
期末复习综合练习题
一.选择题(满分 40 分,每小题 4 分)
1.下列各组数据不是勾股数的是( )
A.2,3,4
B.3,4,5
C.5,12,13
D.6,8,10
人教版八年级数学下册期末复习填空题含答案
人教版八年级数学下册期末复习填空题含答案第16章二、填空题(每小题3分,共18分)13.计算:13 ×27 =__3__.14.在实数范围内分解因式:x 5-9x =.15.如果两个最简二次根式3a -1 与2a +3 能合并,那么a =__4__.16.如图,在数轴上点A 表示的数为a ,化简:a +a 2-4a +4 =__2__.17.已知a -b =- 2 ,ab =13 ,则代数式a 2+b 2-2ab +a 2+b 2+ab 的值等于_.18.观察下列各式:12+1 = 2 -1,13+2 = 3 - 2 ,14+3= 4 - 3 ,……请你从上述等式中找出规律,并利用这一规律计算:⎝ ⎛⎭⎪⎫13+2+14+3+15+4+……+12 020+ 2 019 ( 2 020 + 2 )=__2_018__.第17章二、填空题(每小题3分,共18分)13.在Rt △ABC 中,∠C =90°,若a ∶b =3∶4,c =20,则a =__12__,b =__16__.14.若边长为a 的正方形的面积等于长为b +c ,宽为b -c 的长方形的面积,则以a ,b ,c 为三边长的三角形是__直角__三角形.15.如图,在Rt △ABC 中,∠ACB =90°,AC =5 cm ,BC =12 cm.以BC 为边作等边三角形△BCD,CD交AB于点F,过D作DE⊥DB,使DE=AC,连接BE,则△ACF和△BDF的周长之和为__42__cm.16.如图,C为线段BD上一动点,分别过点B,D作AB⊥BD,ED⊥BD,连接AC,EC,已知AB=5,DE=1,BD=8,AC+CE的最小值为__10__.第16题图17.如图是一个外轮廓为矩形的机器零件平面示意图,根据图中标出的尺寸(单位:mm)计算两圆孔中心A和B的距离为__150_mm__.第17题图18.如图所示,在△ABC中,AB∶BC∶CA=3∶4∶5,且周长为36 cm,点P从点A开始沿AB边向B点以每秒1 cm的速度移动;点Q从点B沿BC边向点C以每秒2 cm的速度移动,如果同时出发,则第3秒,△BPQ的面积为__18__cm2.第18题图第18章二、填空题(每小题3分,共18分)13.如图,若直线AE∥BD,点C在直线BD上,且AE=5,BD=8,△ABD 的面积为16,则△ACE的面积为__10__.第13题图14.菱形周长为40,一条对角线长为16,则另一条对角线为__12__,这个菱形的面积为__96__.15.如图,将Rt△ACB沿直角边AC所在直线翻折180°,得到Rt△ACE,点D,F分别是斜边AB,AE的中点,连接CD,CF,则四边形ADCF的形状是__菱形__.第15题图16.(哈尔滨中考)如图,在矩形ABCD中,M为BC边上一点,连接AM,过点D作DE⊥AM,垂足为E,若DE=DC=1,AE=2EM,则BM的长为5__.第16题图17.如图,正方形ABCD中,E为AB的中点,FE⊥AB,AF=2AE,FC交BD于点O,则∠DOC的度数为__60°__.第17题图18.(深圳中考)如图,CB=CA,∠ACB=90°,点D在边BC上(与B,C不重合),四边形ADEF为正方形,过点F作FG⊥CA,交CA的延长线于点G,连接FB,交DE于点Q,给出以下结论:①AC=FG;②S△FAB∶S四边形CBFG=1∶2;③∠ABC =∠ABF ,其中正确结论的序号是__①②③__.第18题图期中复习二、填空题(每小题3分,共18分)13.要使代数式x +13x -2在实数范围内有意义,则x 的取值范围为__x ≥-1且x ≠23 __.14.(淮安中考)在四边形ABCD 中,AB =DC ,AD =BC ,请再添加一个条件,使四边形ABCD 是矩形.你添加的条件是__∠A =90°或∠B =90°或∠C =90°或∠D =90°或AC =BD__.(写出一种即可)15.已知a 2+b -2 =4a -4,则ab 的平方根是__±_.16.如图,两个正方形的面积分别是64和49,则AC 的长为__17__. 第16题图17.(丽水中考)我国三国时期数学家赵爽为了证明勾股定理,创制了一副“弦图”,后人称其为“赵爽弦图”,如图①所示,在图②中,若正方形ABCD 的边长为14,正方形IJKL 的边长为2,且IJ ∥AB ,则正方形EFGH 的边长为__10__.第17题图18.如图,正方形ABCD 中,点E ,F 分别在边BC ,CD 上,且AE =EF =FA.有下列结论:①△ABE ≌△ADF ;②CE =CF ;③∠AEB =75°;④BE +DF =EF ;⑤S △ABE +S △ADF =S △CEF .其中正确的是__①②③⑤__(只填写序号). 第18题图第19章二、填空题(每小题3分,共18分)13.A ,B 两地相距180千米,火车由A 地驶往B 地,行驶的速度为160千米/时,它距离B 地的路程s(千米)与所行驶的时间t(时)之间的关系式是__s =180-160t__,s 是t 的__一次__函数.14.直线y =3x -12与x 轴交点坐标是__(4,0)__,与y 轴的交点坐标是__(0,-12)__,与两坐标轴围成的三角形的面积是__24__.15.已知函数y =2x -1与函数y =52 -32 x 的图象交点如图所示,则方程组⎩⎪⎨⎪⎧3x +2y =5,2x -y =1 的解为__⎩⎪⎨⎪⎧x =1,y =1 __. 第15题图16.某市出租车收费标准如下表,设行驶的路程为x 千米,出租车的运价为y 元,则当0≤x ≤3时,y =__6__;当x>3时,y 与x 的函数关系式为__y =2.1x -0.3__.17.如图,经过点B(-2,0)的直线y =kx +b 与直线y =4x +2相交于点A(-1,-2),则不等式4x +2<kx +b<0的解集是__-2<x<-1__.18.如图,在平面直角坐标系中,等边△ABC 的边BC 在x 轴上,其中点B(2,0),C(4,0).将△ABC 向左平移,当点A 落在直线y =12 x +1上时,平移的距离是.第20章二、填空题(每小题3分,共18分)13.某招聘考试分笔试和面试两种,其中笔试按60%,面试按40%计算加权平均数,作为总成绩.孔明笔试成绩90分,面试成绩85分,那么孔明的总成绩是__88__分.14.数据1,2,3,2,3,2,4的平均数是__177 __,众数是__2__,中位数是__2__.15.(北海中考)一组数据:1,-1,0,4的方差是__3.5__.16.(2018·青岛)已知甲、乙两组数据的折线图如图所示,设甲、乙两组数据的方差分别为s 2甲 ,s 2乙 ,则s 2甲 __>__s 2乙 (选填“>”“=”或“<”). 17.一组数据9,9,x ,7的众数与平均数相等,则中位数是__9__.18.下列几种说法:①数据2,2,3,4的众数为2;②数据1,0,0,1,0的中位数和众数相等;③数据11,11,11,11,11的方差为1;④若一组数据a ,b ,c 的平均数为10,则新数据a +1,b +1,c +1的平均数为10;⑤已知一组数据x 1,x 2,…,x n 的方差是s 2,则新的一组数据ax 1+1,ax 2+1,…,ax n +1(a 为常数,a ≠0)的方差是a 2s 2.其中正确的有__①②⑤__.(填序号即可)期末复习一二、填空题(每小题3分,共18分)13.计算:(48 -327 )÷ 3 =__-5__.14.(广州中考)一次函数y =(m +2)x +1,若y 随x 的增大而增大,则m 的取值范围是__m>-2__.15.样本数据3,6,a ,4,2的平均数是5,则这个样本的方差是__8__.16.已知直角坐标平面内的△ABC 三个顶点A ,B ,C 的坐标分别为(4,3),(1,2),(3,-4),则△ABC 的形状是__直角三角形__.17.甲乙两地相距50千米,星期天上午8:00小聪同学在父亲陪同下骑山地车从甲地前往乙地.2小时后,小明的父亲骑摩托车沿同一路线也从甲地前往乙地,他们行驶的路程y(千米)与小聪行驶的时间x(小时)之间的函数关系如图所示,小明父亲出发__23 或43 __小时,行进中的两车相距8千米.第17题图18.如图,已知平面直角坐标系中的三点分别为A(2,3),B(6,3),C(4,0).现要找到一点D ,使得四个点构成的四边形是平行四边形,那么点D 的坐标是__(0,0)或(4,6)或(8,0)__.第18题图期末复习二二、填空题(每小题3分,共18分)13.计算( 3 -2)( 3 +2)的结果是__-1__.14.近年来,A 市市民汽车拥有量持续增长,2014年至2018年该市汽车拥有量(单位:万辆)依次为11,13,15,19,x.若这五个数的平均数为16,则x =__22__.15.若一条直线经过点(-1,1)和点(1,5),则这条直线与x 轴的交点坐标为__⎝ ⎛⎭⎪⎫-32,0 __. 16.(2018·咸宁)如图,将正方形OEFG 放在平面直角坐标系中,O 是坐标原点,点E 的坐标为(2,3),则点F 的坐标为__(-1,5)__.第16题图17.(2018·温州)如图,直线y =-33 x +4与x 轴,y 轴分别交于A ,B 两点,点C 是OB 的中点,点D 是AB 上一点,四边形OEDC 是菱形,则△OAE 的面积为.第17题图18.(2018·重庆)A,B两地之间的路程为240 km,甲、乙两车沿同一线路从A 地出发到B地,分别以一定的速度匀速行驶.甲车先出发40 min后,乙车才出发,途中乙车发生故障,修车耗时20 min.随后,乙车车速比发生故障前减少了10 km/h(仍保持匀速前行),且甲、乙两车同时到达B地.若甲、乙两车之间的路程y(km)与甲车行驶时间x(h)之间的关系如图所示,则乙车修好时,甲车离B地的路程还有__90__km.。
人教版 八年级下册 unit3单词填空专项练习(80道)
人教版八年级下册unit3单词填空专项练习A组课堂练习根据首字母或汉语提示,填入单词。
1.-Would you like some coffee or milk? - E_______ is OK. I'm thirty.2.We s________ the floor just half an hour ago.3.A l________ room is a place where people watch TV and talk with friends and family members.4.The room is very dirty. Could you c_________ it now?5.We p_________ nice food for them. They were very happy.6.Now lots of children don't understand the idea of f________(公正性).7.-Do you often help your parents do c_________ at home?-Yes, I clean the living room every day.8.-Can I b_______ your bike when I go to the party this evening? - Sure.9.He really_______ (讨厌) making his bed.10.I forgot to take my umbrella with me, so I got______________(湿的) when I arrived home.11.I think 5 dollars is e_______ for the book.12.They think doing chores is a _______ (浪费) of time.13.Many people don't like to depend on their parents. They hope to be i_________.14.We often buy some drinks and s________ after school.15.Mother certainly won’t let him stay with them and ________(而且) he wouldn’t.16.You shouldn’t ____your parents completely.(依赖)17.Mary lives on the 10th f__________ in the apartment.18.He went into the room and s_______ down in front of the TV.19.Tom,please help me f________ the clothes on the sofa.20.Here is a lot of r__________. Could you take it out?21.The five-year-old boy d_________ his bowl and broke it.22.I bought a white______________(衬衫) for my father as a birthday present.23.Children shouldn’t d_________ on their parents too much.24.Please f__________ your clothes. Don't put them everywhere.25.You look worried. What h_________?26.My mother was badly i________ and we took her to the hospital.27.Tom is wearing a blue ________(衬衫)today.28.Why do some parents make their kids _____(drink) milk every day?29.I don’t want to do chores and ____.(他也不想)30.My mother often cooks delicious food in the k__________.31.The _________(结果)of the match is surprising.32.Please show me your ten_______ (手指).33.____pass the exam, he studies hard every day.(为了)34.Lucy’s mother asks her ____herself after she gets up in the morning.(整理床铺)35.Chen Bin didn’t come to school because he ____yesterday.(患病)36.There is no n_____ for kids to do housework now.37.Doing chores helps to develop children’s_______ (独立).38.-Could you please help me with my English? -Yes, s_________.39.N_______ of the twins likes sports. But both of them like music.40.China is not like America, but still a _______(发展) country.B组课后巩固根据首字母或汉语提示,填入单词。
新版人教版初二物理下册填空题专项训练
一、填空题1、力是一个 对另一个 的作用,因此力不能脱离 而存在。
由此可见,一个力肯定同时涉及两个物体,其中一个叫 物体,另一个叫 物体。
2、一个苹果或两个较小的鸡蛋放在手中静止时,对手的压力约为 ,一名普通的中学生站在地面上,对地面的压力约为 。
3、力的作用效果表现在两个方面:①改变物体的 ② 改变物体的 。
扩展:力能使物体的运动状态发生变化,力可以使运动的物体 下来,也可以使静止的物体 起来,还可以使物体的运动速度 、 发生变化等。
4、力的三要素是指力的大小、方向和 。
5、重垂线是根据________的原理制成的,建筑工人常用它来检查墙壁______________,木工常用它来检查工作台______________.6、一本书放在水平桌面上,书受到桌面的 力;这个力的施力物体是 ,受力物体是 .同时这本书对桌面产生,这个力的施力物体是 ,受力物体是___ ___。
7、人拉弹簧,拉力使弹簧变形了, 即发生了 __,守门员把飞向球门的球踢回去,设球来去的速度大小不变,踢球的力改变了足球运动的___ ___,即改变足球的_____________.8、 如图所示,图(ABC)表示力可以改变物体的 .图(D)表示力可以改变物体的 .9、在物体所受重力跟质量的关系式 中,G 代表 、m 代表 、人对跳板的压力 手对弓的拉力手对弹簧的拉力 磁铁对小铁球的吸引力 A B CDg = ,读作 ,它表示10、一座限重为5×104N 的桥,一辆自身质量为1.1t 的卡车要能安全过桥,所能装载的货物不能超过___________ kg .(g=10N/kg )12.人们有时要利用惯性带来的好处,有时要防止惯性带来的危害,请你就惯性的两面性各写出一例(不要求作解释)⑴利用:⑵防止:13.摩擦力有时对我们有害,因此人们想到各种方法减小有害摩擦,请你列举生活或生产技术中用两种不同方法减小摩擦力的例子⑴⑵14. 如图9甲所示,完全相同的木块A 和B 叠放在水平桌面上,在12N 的水平拉力F 1作用下,A 、B 一起作匀速直线运动,此时木块B 所受的摩擦力为 N ;若将A 、B 紧靠着放在水平桌面上,用水平力F 2推A 使它们一起匀速运动(如图9乙所示),则推力F 2= N 。
人教版八年级下册英语综合填空10篇(有答案)
(一)Lin Feng _____ (wake) up at five o'clock in the morning. He didn't feel well. "What's the matter _____ me?" he thought to _____ (he). "Am I sick?" He wanted to say _____ (anything), but he found he had a sore throat. And he felt his body was hot.Lin Feng got out of bed. He drank some water in the kitchen. Then he took out the thermometer (体温计) and _____ (lie) down again. He took his _____. It was almost 39℃. It showed he had a fever. "I should take some medicine," he thought. But he was so tired _____ he didn't want to move. Soon he fell asleep again.Three hours _____ (late), Lin Feng got up and went to the hospital. The doctor said he _____ rest at home. Lin Feng got some medicine from a nurse and went back home. "I was too busy last month," he thought. "Maybe it's time to take _____ (break)."答案:woke with himself something lay temperature that later must/should breaks(二)Kangkang looks _____ (exciting) now. He is talking about the movie The Sound of Music with his classmates. He invited his classmates _____ (go) to see the movie yesterday, and it didn't make them _____ (disappoint).The Sound of Music is one of the most popular American movies. It tells the story about a young Austrian woman _____ Maria. Maria was sent to the Von Trapp family to teach Mr. Van's seven children and care _____ them. The Von family lived a happy life before. But _____ Mrs. Van died of illness, the family were very sad. The children cried and shouted every day. Mr. Vanfelt _____ (lone) and often became angry _____ the noisy children. After Maria came to the family, she taught the children to sing _____ (live) songs and perform plays to cheer them ____. Seeing the smiling faces of his children, Mr. Van was happy again.Kangkang thinks the movie is worth seeing several times and he plans to see it again with his parents this Sunday.答案:excited to go disappointed called/named for after lonely with lively up(三)Dear Abby,I'm a helpless mother. My son is 15 years old. I find that the _____(old) he grows, the less we talk. I feel very worried and I _____(real) need help.My first problem is about his hobbies. He seems to spend too muchtime _____ computer games. As soon _____ he gets home, he always turns on the computer, closes the door and locks others out. I'm getting worried about _____(he), especially when his English _____(teach) told me he always failed in the English exams.Second, it seems that he is crazy about the new technology. However, tobe _____(honesty), I don't have enough money and I can't afford allthe _____(thing) he wants.Recently, I _____(find) that he is always alone. I've never seen him talking to his friends on the phone or going out with anyone on weekends. Thatis _____ last problem I have.Do all the boys behave this way? What should I do to help him?答案:older really on as him teacher honest things have found the(四)Students these days often have a lot of _____ (worry). Sometimes they have problems with their schoolwork, and sometimes with their friends. What can they do about this? Some people believe the worst thing is _____ (do) nothing. Laura Mills, a teenager _____ London, agrees. "Problems and worries are normal in life," says Laura. "But I think talking to someone _____ (help) a lot. Unless we talk to someone, we __5__ certainly _____ (feel) worse."Laura once lost her wallet, and worried for days. She was afraid _____ (tell) her parents about it. She even walked three miles to school eachday _____ she didn't have any money. She just kept _____ (think), "If I tell my parents, they'll be angry!" In the end, she talked to her parents and they were really _____ (understand). Her dad said he sometimes made careless mistakes himself. They got her a new wallet and asked her to be more careful. "I will always remember _____ (share) my problems in the future!" Laura says.答案:worries to do from helps will feel to tell because thinking understanding to share(五)We can use cameras to take photos. Can cats do it? Believe it or not, there is a cat that can use cameras _____(take) photos. Read on and find out more information.The name _____ the cat is Cooper. He is a five-year-old cat and he _____(live) in Seattle, America. He is very special because he is the only cat who has his own camera.At the _____(begin), Cooper's owner puts a camera on his neck. He just wants to learn about the _____(cat) life from the camera.When Cooper _____ (bring) the camera home at the end of the first day, the photos that he took surprised his owner. Many _____(beauty) pictures filled Cooper's day.It is _____(real) interesting to be able to see the world from a cat's eye. Cooper's owner says that these photos let people see into a cat'sworld, _____ also help them to learn more about their pets.Cooper now has more than 12,000 fans on _____ Internet and has even made TV shows in America.答案:to take of lives beginning cat’s brought beautiful really and the(六)Many people like the story called Alice's Adventures inWonderland _____ Lewis Carroll. The _____ (write) real name is Charles Dodgson._____ the story, Alice met some unusual people when she went to Wonderland. She was sitting by the river and _____ (feel) tired. Suddenly she saw a white rabbit with pink _____ (eye). The rabbit took out _____ watch from the pocket and had a look. Alice jumped up and _____ (follow) the rabbit when it went down into a deep hole. Then she came to a garden and found a cat on the ground. When she spoke to the cat, she saw it _____ (smile). Thenshe met the Mad Hatter and the March Hare _____ they were having a tea party. At _____ she met a king and a queen. She had a really wonderful time in Wonderland.答案:by writer’s In feeling/felt eyes its followed smiling when last(七)Dear Lisa,My parents and I are having a wonderful time in Zhangjiajie. It's a magic land of mountains, forests and rivers. It's very large, about 480 _____ (kilometre)s. It's famous for the strange shape of _____ (it) tall rocks. Some looklike _____ (human) while others look like wild animals.Last night we camped by a small lake. At midnight, a noise woke us _______. We thought _____ (anybody) was moving about. My father came out without making a noise and found it was a hungry monkey looking for food.This morning, we climbed Mount Tianzi. We took some pictures _____ the top of it. But it was a pity that it was so _____ (cloud) that we couldn't see far away. Then we walked down the path. I picked up a leaf from a plant, but my father said _____ it was wrong _____ (pull) leaves off a plant and that we should protect everything here.Tomorrow we're going to Dongting Lake, the second _____ (large) freshwater lake in China. I'm sure it'll be a fantastic trip.Yours,Betty答案:kilometres its humans up somebody at cloudy that to pull largest(八)In a primary school, a teacher asked her students what they wished to become when they grew up. There were several _____ (answer)一a doctor, a teacher, a film star and so on.One of the students gave a _____ (surprise) answer. This child said, "I want to be a television!" The teacher asked the child why he had such a wish. He said, with his eyes full _____ tears, "There is no one at home _____ (watch) me or care for me. Everyone sits around the television. If there is anythingwrong _____ the TV. they give great attention to it and fix it at once."The loving teacher met the child's mother and _____ (talk) about this with her. The mother said. "My husband is a very busy businessman. Henever _____ (have) time to look after the child." "But what about you?" the teacher asked the mother. "What do you know about me? I'm the president of the women's club. I have _____ many meetings and activities." The teacher now _____ (understand) why the child felt _____ (alone) at home."I think children need their parents to spend much time with them," said the teacher.答案:answers surprising of to watch with talked has so undstood lonely(九)The computer is a_____(use) machine. It is one of the most important_____(invent) in many years. A computer then could do Maths problems very_____(quick). Today computers are used_____many ways and can do many kinds of work. In a few years the computer may touch_____life of everyone, even people in the faraway villages. In the last few years, there have been great_____(change) in computers. They are getting smaller and smaller, and_____(calculate) faster and faster. Many scientists agree that computers can now do many things,_____they cannot do everything. Who knows_____the computers of tomorrow will be like? Will computers bring good things or bad things to people? The scientists of today will have to decide how_____(use) the computers of tomorrow.答案:useful inventions quickly in the changes calculating but what to use(十)It's Sunday. It is yard _____ (sell) time again, and everyone in the Jones family decides to sell things that they no _____ (long) use.Billy clears out his old toys. _____ he doesn't want to lose his train and railway set, which he has owned _____ his fourth birthday, he still puts them in the box. He also finds some clothes that don't fit. Suzy decides to part _____ some soft toys from her collection. She also finds some old books. Dad gives up his records that he isn't interested in anymore. To be _____, he hasn't listened to them _____ a really long time. Mom has a few things to sell, such as handbags, shoes and clothes. One last thing is her bread _____ (make).She _____ (have) it for a long time but it still works.In the end, Billy makes $22, and Suzy makes $18. Mom and Dad make abit _____ (much). It is quite a good day.答案:sale longer although/though since with honest for maker has had more。
人教版 八年级数学下册 期末综合复习(含答案)
人教版 八年级数学下册 期末综合复习一、选择题(本大题共12道小题) 1. 计算(2x +1)(2x -1)的结果为 ( ) A .4x 2-1B .2x 2-1C .4x -1D .4x 2+12. 把分式方程2x +4=1x 转化为一元一次方程时,方程两边需同乘( ) A .xB .2xC .x +4D .x (x +4)3. 若a 2+ab +b 2=(a -b )2+X ,则整式X 为()A .abB .0C .2abD .3ab4. 如图,△ABE ≌△ACD ,∠A =60°,∠B =25°,则∠DOE 的度数为()A .85°B .95°C .110°D .120°5.(2020·临沂)如图,在ABC ∆中,AB AC =,40A ∠=︒,//CD AB ,则BCD ∠=( )A.40°B.50°C.60°.D.70°6. 下列哪一个度数可以作为某一个多边形的内角和 () A .240° B .600°C .540°D .2180°7. (2020·天津)计算221(1)(1)x x x +++的结果是( )A.11x+B.21(1)x+C. 1D. 1x+8. 如图,在△ABC中,AB=AC,以点C为圆心,CB长为半径画弧,交AB于点B和点D,再分别以点B,D为圆心,大于12BD长为半径画弧,两弧相交于点M,作射线CM交AB于点E.若AE=2,BE=1,则EC的长度是A.2 B.3C3D59. 下列长度的三条线段能组成钝角三角形的是( )A. 3,4,4B. 3,4,5C. 3,4,6D. 3,4,710.如图,平行河岸两侧各有一城镇P,Q,根据发展规划,要修建一条公路连接P ,Q两镇.已知相同长度造桥总价远大于陆上公路造价,为了尽量减少总造价,应该选择方案( )11. 如图为6个边长相等的正方形的组合图形,则∠1+∠2+∠3等于( )A.90°B.120 C.135°D.150°12.如图,在△CEF中,∠E=80°,∠F=50°,AB∥CF,AD∥CE,连接BC,CD ,则∠A的度数是( )A.45°B.50°C.55°D.80°二、填空题(本大题共12道小题)13.图中的虚线,哪些是图形的对称轴,哪些不是?是对称轴的是______;不是对称轴的是______.(填写序号)14. (2020·武威)分解因式:a2+a=.15.如图,已知在△ABC和△DEF中,∠B=∠E,BF=CE,点B,F,C,E在同一条直线上,若使△ABC≌△DEF,则还需添加的一个条件是________(只填一个即可).16.如图,两车从南北方向的路段AB的A端出发,分别向东、向西行进相同的距离,到达C,D两地,此时可以判断C,D到B的距离相等,用到的数学道理是____ ____.17.将两块完全相同的三角尺在∠AOB的内部如图摆放,两块三角尺较短的直角边分别与∠AOB的两边重合,且含30°角的顶点恰好也重合于点C,则射线OC即为∠AOB的平分线,理由是______________________.18.如图,∠AOB=40°,C为OB上的定点,M,N分别为OA,OB上的动点,当CM +MN的值最小时,∠OCM的度数为________.19. 将分式1a2-9和a3a-9进行通分时,分母a2-9可因式分解为____________,分母3a-9可因式分解为__________,因此最简公分母是____________.20. 若a-b=3x-y=2则a2-2ab+b2-x+y=________.21.如图,BO平分∠CBA,CO平分∠ACB,MN过点O且MN∥BC,设AB=12,AC =18,则△AMN的周长为________.22. 计算:1x2-6x+9÷x+3x-3·(9-x2).解:原式=1(x-3)2÷x+3x-3·(3+x)(3-x)……第一步=1(x-3)2·x-3x+3·(3+x)(3-x)……第二步=1.……第三步回答:(1)上述过程中,第一步使用的公式用字母表示为__________________________;(2)由第二步得到第三步所使用的运算方法是____________;(3)以上三步中,从第________步开始出现错误,本题的正确答案是__________.23. 一个等腰三角形的一边长是2,一个外角是120°,则它的周长是________.24. 画图:试画出下列正多边形的所有对称轴,并完成表格.根据上表,猜想正n边形有条对称轴.三、作图题(本大题共2道小题)25.利用刻度尺和三角尺作图:如图所示,已知四边形ABCD和直线m.请你作出四边形A1B1C1D1,使得四边形A1B1C1D1和四边形ABCD关于直线m成轴对称.26. 如图,在河岸l的同侧有两个居民小区A,B,现欲在河岸边建一个长为a的绿化带CD(宽度不计),使C到小区A的距离与D到小区B的距离之和最小.在图中画出绿化带的位置,并写出画图过程.四、解答题(本大题共6道小题)27. 如图,在△ABC中,AB边的垂直平分线DE分别与AB边和AC边交于点D 和点E,BC边的垂直平分线FG分别与BC边和AC边交于点F和点G,若△BEG 的周长为16,GE=3,求AC的长.28. 我们知道:分式和分数有着很多的相似点.如类比分数的基本性质,我们得到了分式的基本性质.小学时,把分子比分母小的分数叫做真分数.类似地,我们把分子的次数小于分母的次数的分式称为真分式,反之,称为假分式.对于任何一个假分式都可以化成整式与真分式的和的形式,如==+=1+. (1)下列分式中,属于真分式的是()A.B.C.-D.(2)将假分式化成整式与真分式的和的形式.29. 整体代入阅读下面文字,并解决问题.已知x2y=3,求2xy(x5y2-3x3y-4x)的值.分析:考虑到满足x2y=3的x,y的可能值较多,不可能逐一代入求解,故考虑整体思想,将x2y=3整体代入.解:2xy(x5y2-3x3y-4x)=2x6y3-6x4y2-8x2y=2(x2y)3-6(x2y)2-8x2y=2×33-6×32-8×3=2×27-6×9-8×3=-24.请你用上述方法解决问题:已知ab=3,求(2a3b2-3a2b+4a)·(-2b)的值.30.如图,已知AP∥BC,∠P AB的平分线与∠CBA的平分线相交于点E,过点E的直线分别交AP,BC于点D,C.求证:AD+BC=AB.31. 在△ABC中,∠A=90°,∠B=30°,AC=6 cm,点D从点A出发以1 cm/s的速度向点C运动,同时点E从点C出发以2cm/s的速度向点B运动,设运动时间为t s,解决以下问题:(1)当t为何值时,△DEC为等边三角形?(2)当t为何值时,△DEC为直角三角形?32. 已知有理数x ,y ,z 满足2|2|(367)|334|0x z x y y z --+--++-=,求3314n n n x y z x--的值.人教版 八年级数学下册 期末综合复习-答案一、选择题(本大题共12道小题) 1. 【答案】A2. 【答案】D3. 【答案】D4.【答案】C [解析]∵△ABE ≌△ACD ,∴∠B =∠C =25°.∵∠A =60°,∠C =25°,∴∠BDO =∠A +∠C =85°.∴∠DOE =∠B +∠BDO =85°+25°=110°.5. 【答案】D【解析】 根据三角形内角和定理和等腰三角形的等边对等角且AB AC =,40A ∠=,可得:70ABC ACB ∠=∠=;然后根据两直线平行内错角相等且//CD AB 可得:70BCD ABC ∠=∠=,所以选D .6. 【答案】C[解析] ∵多边形内角和公式为(n -2)×180°,∴多边形内角和一定是180°的倍数. ∵540°=3×180°,∴540°可以作为某一个多边形的内角和.7. 【答案】A【解析】本题考查分式的加减运算,主要运算技巧包括通分,约分,同时常用平方差、完全平方公式作为解题工具.本题可先通分,继而进行因式约分求解本题.221(1)(1)x x x +++21(1)x x +=+,因为10x +≠,故211=(1)1x x x +++.故选:A .8. 【答案】D【解析】由作法得CE ⊥AB ,则∠AEC=90°, AC=AB=BE+AE=2+1=3,在Rt △ACE 中,=.故选D .9.【答案】C【解析】①∵32+42=52,∴三条线段3、4、5组成直角三角形,∴B 选项不正确;②当把斜边5变成7时,3+4=7,不满足三角形两边之和大于第三边,不能构成三角形,∴D 选项不正确;③当把斜边5稍微变小一点为4时,三条线段为3、4、4组成锐角三角形,∴A 选项不正确;④当把斜边5稍微变大一点为6时,三条线段为3、4、6组成钝角三角形,∴C 选项正确.10.【答案】C [解析]如图,作PP′垂直于河岸L ,使PP′等于河宽,连接QP′,与河岸L 相交于点N ,将P′N 沿竖直方向向上平移河宽个单位长度,得到PM ,PM -MN -NQ 即所求.根据“两点之间,线段最短”,QP′最短,即PM +NQ 最短.观察选项,选项C 符合题意.11.【答案】C [解析]在图中容易发现全等三角形,将∠3转化为与其相等的对应角后可以看出∠3与∠1互余.故∠1+∠3=90°.易得∠2=45°,故∠1+∠2+∠3=135°.12. 【答案】B[解析] 如图,连接AC 并延长交EF 于点M.∵AB ∥CF ,∴∠3=∠1. ∵AD ∥CE ,∴∠2=∠4.∴∠BAD =∠3+∠4=∠1+∠2=∠FCE.∵∠FCE =180°-∠E -∠F =180°-80°-50°=50°,∴∠BAD =∠FCE =50°.二、填空题(本大题共12道小题)13. 【答案】②④⑥①③⑤14. 【答案】a 2+a =a (a +1).故答案为:a (a +1).15. 【答案】答案不唯一,如AB =DE[解析] ∵BF =CE ,∴BC =EF. 在△ABC 和△DEF 中,⎩⎪⎨⎪⎧AB =DE ,∠B =∠E ,BC =EF ,∴△ABC ≌△DEF(SAS).16. 【答案】线段垂直平分线上的点与这条线段两个端点的距离相等17. 【答案】角的内部到角的两边距离相等的点在角的平分线上18.【答案】10° [解析]作点C 关于OA 的对称点D ,过点D 作DN ⊥OB 于点N ,交OA 于点M ,则此时CM +MN 的值最小.∵∠OEC =∠DNC =90°,∠DME =∠OMN , ∴∠D =∠AOB =40°.∵MD=MC,∴∠DCM=∠D=40°,∠DCN=90°-∠D=50°.∴∠OCM=10°.19. 【答案】(a+3)(a-3)3(a-3)3(a+3)(a-3)20. 【答案】7[解析] a2-2ab+b2-x+y=(a-b)2-(x-y).把a-b=3x-y=2代入得原式=32-2=7.21. 【答案】30 [解析] ∵MN∥BC,∴∠MOB=∠OBC.∵∠OBM=∠OBC,∴∠MOB=∠OBM.∴MO=MB.同理NO=NC.∴△AMN的周长=AM+MO+AN+NO=AM+MB+AN+NC=AB+AC=30.22. 【答案】(1)a2-2ab+b2=(a-b)2,a2-b2=(a+b)(a-b)(2)约分(3)三-123. 【答案】 6 [解析] 已知三角形的一外角为120°,则相邻内角度数为60°,那么含有60°角的等腰三角形是等边三角形.已知等边三角形的一边长为2,则其周长为6.24. 【答案】解:如图.故填3,4,5,6,n.三、作图题(本大题共2道小题)25. 【答案】解:如图,四边形A1B1C1D1即为所求.26. 【答案】解:如图,作线段AP∥l,使AP=a,且点P在点A的右侧;作点P关于直线l的对称点P',连接BP'交l于点D;在l上点D的左侧截取DC=a,则CD就是所求绿化带的位置.四、解答题(本大题共6道小题)27. 【答案】解:∵DE垂直平分线段AB,GF垂直平分线段BC,∴EB=EA,GB=GC.∵△BEG的周长为16,∴EB+GB+GE=16.∴EA+GC+GE=16.∴GA+GE+GE+GE+EC=16.∴AC+2GE=16.∵GE=3,∴AC=10.28. 【答案】解:(1)C(2)==+=m-1+.29. 【答案】解:(2a3b2-3a2b+4a)·(-2b)=-4a3b3+6a2b2-8ab=-4(ab)3+6(ab)2-8ab=-4×33+6×32-8×3=-108+54-24=-78.30. 【答案】证明:如图,在AB 上截取AF =AD ,连接EF.∵AE 平分∠PAB ,∴∠DAE =∠FAE.在△DAE 和△FAE 中,⎩⎪⎨⎪⎧AD =AF ,∠DAE =∠FAE ,AE =AE ,∴△DAE ≌△FAE(SAS).∴∠AFE =∠ADE.∵AD ∥BC ,∴∠ADE +∠C =180°.又∵∠AFE +∠EFB =180°,∴∠EFB =∠C.∵BE 平分∠ABC ,∴∠EBF =∠EBC.在△BEF 和△BEC 中,⎩⎪⎨⎪⎧∠EFB =∠C ,∠EBF =∠EBC ,BE =BE ,∴△BEF ≌△BEC(AAS).∴BF =BC.∴AD +BC =AF +BF =AB.31. 【答案】(1)根据题意可得AD =t ,CD =6-t ,CE =2t. ∵△DEC 为等边三角形,∴CD =CE ,即6-t =2t ,解得t =2.∴当t 的值为2时,△DEC 为等边三角形.(2)∵∠A =90°,∠B =30°,∴∠C =60°. ①当∠DEC 为直角时,∠EDC =30°,∴CE =12CD ,即2t =12(6-t),解得t =65;②当∠EDC 为直角时,∠DEC =30°,∴CD =12CE ,即6-t =12·2t ,解得t =3.综上,当t 的值为65或3时,△DEC 为直角三角形.32. 【答案】【解析】由题意得2036703340x z x y y z --=⎧⎪--=⎨⎪+-=⎩,解方程组得3131x y z =⎧⎪⎪=⎨⎪⎪=⎩,代入所求代数式得313133143411313331333033n n n n n n n x y z x ---⎛⎫⎛⎫-=⋅⋅-=⋅⨯⋅-=-= ⎪ ⎪⎝⎭⎝⎭.。
2020年人教版英语八年级下册期中复习 综合填空专练(有答案)
期中复习:综合填空专练一、Dear Peter,I’m writing to tell you about what happened to me last week while I ( 1) ______ (visit) my aunt. One afternoon I ( 2) ______ (take) her dog for a walk when I ( 3) ______ (notice) a girl climbing a tree by the edge of the cliff (悬崖边). Suddenly the branch (树枝) ( 4) ______ (break) and the girl ( 5) ______ (fall) over the edge. I ( 6) ______ (think) about what to do when a man ( 7) ______ (come) along the road. I ( 8) ______ (explain) what had happened and when he ( 9) ______ (go) for help, I (10) ______ (talk) to the girl. Well, everything ended happily.That’s all my news. Write and tell me yours soon.Yours,Lucy1. was visiting2. was taking3. noticed4. broke5. fell6. was thinking7. came8. explained9. went 10. was talking二、阅读下面短文,用括号内所给动词的适当形式填空(必要时可加情态动词或助动词)There was a boy who was forced to a boarding (寄宿的) school by his parents. Before being sent away, this boy used to be the best student in his class. He was at the top in every competition. But things (1)(change) after he went to the new school. His grades began (2)(drop).He hated being in a group. He was lonely all the time. He felt he was worthless and that no one loved him.His parents began to worry about him. But they did not know what was wrong with him. So his dad decided (3)(visit) the school and have a talk with him by himself.They sat on the beach near the school. The father started asking him questions about his classes, teachers and sports with a smile on his face. After some time his dad said kindly, “Do you know why I am here today, my dear son?”The boy answered back quickly, “I know what I (4)(do) makes you sad. So you come here (5)(check) my grades.”“No, no.” his dad replied calmly, “I am here to make you (6)(understand) that you are the most important person for me. I don’t care about grades. I care about you. Nothing can be more meaningful than your happiness for me.Nobody (7)(be) more valuable than you for me. You are my life!”These words made the boy’s ey es filled with tears.He hugged his dad happily. They didn’t say anything to each other for a long time.Then the boy knew that his parents (8)(care) for him deeply when he lost himself. He meant the world to someone. And now this young man (9)(study) in college and no one has ever seen him sad. He often tells himself that he (10) (be) happy forever.1.changed2.to drop/dropping3.to visit4.have done5.to check6.understand7.can be8.were caring9.is studying10.will be三、阅读下面短文,根据短文内容用方框内所给词汇或短语的适当形式填空,使短文语义完整。
人教版八年级数学下册填空题复习及答案
人教版八年级数学下册填空题复习及答案第十六章二、填空题(每小题3分,共24分)11.计算 3 +12 的结果是_.12.将13 化成最简二次根式为_3 __. 13.若(a -6)2 =6-a ,则a 的取值范围是__a ≤6__.14.若最简二次根式32m +5 与54m -3 可以合并,则m =__4__.15.已知x ,y 都是实数,且y =x -3 +3-x -2,则y x =__-8__.16.若12x 是一个整数,则x 可取的最小正整数是__3__.17.我国南宋著名数学家秦九韶在他的著作《数书九章》一书中,给出了著名的秦九韶公式,也叫三斜求积公式,即如果一个三角形的三边长分别为a ,b ,c ,则该三角形的面积为S =14⎣⎢⎢⎡⎦⎥⎥⎤a 2b 2-⎝ ⎛⎭⎪⎫a 2+b 2-c 222 .已知△ABC 的三边长分别为 5 ,2,2,则△ABC 的面积为4 __. 18.已知x =2+ 3 ,则代数式(7-4 3 )x 2+(2- 3 )x - 3 的值为__2-.第十七章二、填空题(每小题3分,共24分)11.若8,a ,17是一组勾股数,则a =__15__.12.已知命题:全等三角形的对应边相等,这个命题的逆命题是:__对应边相等的两个三角形全等__.13.如图,小正方形的边长都为1,则△ABC的三边长a,b,c的大小关系是__c>a>b__(用“>”连接).第13题图14.已知△ABC的三边的长分别是AB=5,BC=4,AC=3,那么∠C=__90°__.15.在△ABC中,∠C=90°,D是BC边上一点,AB=17 cm,AD=10 cm,AC =8 cm,则BD的长为__9_cm__.16.如图是“俄罗斯方块”游戏中的一个图案,由四个完全相同的小正方形拼成,则∠ABC的度数为__45°__.第16题图17.在一棵树CD的10米高处B有两个猴子为抢吃池塘边水果,一只猴子爬下树跑到A处(离树距离AC为20米)的池塘边.另一只爬到树顶D后直接跃到A处,距离以直线计算,如果两只猴子所经过的距离相等,则这棵树高__15__米.18.某园艺公司对一块直角三角形的花圃进行改造,测得两直角边长为5 m,12 m.现要将其扩建成等腰三角形,且扩充部分是以12 m为直角边的直角三角形.则扩建后的等腰三角形花圃的周长为_46.8_m__.第十八章二、填空题(每小题3分,共24分)11.在四边形ABCD 中,AD ∥BC ,在不添加任何辅助线的情况下,请你添加一个条件__AB ∥CD(答案不唯一)__,使四边形ABCD 是平行四边形.12.矩形ABCD 中,对角线AC ,BD 相交于点O ,OA =4,则BD =__8__.13.已知三角形的三边长分别是4,5,6,则它的三条中位线围成的三角形的周长是__7.5__.14.如图,在正方形ABCD 中,点P 是AB 上任意一点,PM ⊥AC ,PN ⊥BD ,垂足分别为点M ,N ,若BD =10,则PM +PN =__5__.15.在菱形ABCD 中,AC =8,菱形ABCD 的面积为24,则菱形ABCD 的周长为__20__.16.如图,将矩形纸片ABCD 沿EF 折叠,使D 点与BC 边的中点D ′重合.若BC =8,CD =6,则CF =__53__. 第16题图 第17题图17.如图,已知△ABC 中,∠ACB =90°,O 为AB 的中点,点E 在BC 上,且CE =AC ,∠BAE =15°,则∠COE =__75°__.18.如图,在正方形ABCD 中,点E 在BC 上,点F 在CD 上,连接AE ,AF ,EF ,∠EAF =45°,BE =3,CF =4,则正方形的边长为__6__.第十九章二、填空题(每小题3分,共24分)11.快餐每盒5元,买n 盒需付m 元,则其中常量是__5__.12.按如图所示的程序计算函数y 的值,若输入x 的值为-3,则输出y 的结果为__18__.13.已知正比例函数y =(k +5)x ,且y 随x 的增大而减小,则k 的取值范围是__k <-5__.14.一次函数y =43 x -b 沿y 轴向上平移3个单位长度得直线y =43x -1,则b 的值为__4__.15.一次函数y 1=kx +b 与y 2=x +a 的图象如图所示,有下列结论:①k <0;②a >0;③当x >4时,y 1<y 2;④b <0.其中正确的结论是__①③__(填序号).第15题图 第17题图16.在平面直角坐标系中,点P 在直线y =x +b 的图象上,且点P 在第二象限,PA ⊥x 轴于点A ,PB ⊥y 轴于点B ,四边形OAPB 是面积为25的正方形,则直线y =x +b 的函数解析式是__y =x +10__.17.如图,已知A 地在B 地正南方3千米处,甲、乙两人同时分别从A ,B 两地向正北方向匀速直行,他们与A 地的距离s(千米)与所行的时间t(小时)之间的函数关系图象用如图所示的AC 和BD 表示,当他们行走3小时后,他们之间的距离为__32__千米. 18.在平面直角坐标系xOy 中,已知点A(-2,0),B(2,0),点P 在直线y= 3 x 上,若△ABP 是直角三角形,则点P 的坐标为_.第二十章二、填空题(每小题3分,共24分)11.某公司想招一名笔译能力较强的翻译,听、说、读、写成绩按照2 ∶1 ∶3 ∶4的比确定,甲应试者的各项成绩如下表:则甲应试者的综合成绩为__80.4__.12.2022年将在北京举办冬季奥运会,北京将成为世界上第一个既举办夏季奥运会,又举办冬季奥运会的城市.某队要从两名选手中选取一名参加比赛,为此对这两名队员进行了五次测试,测试成绩如图所示,__A __选手的成绩更稳定.13.白银市4月1号至4月7号,每天的最高气温分别为8 ℃,11 ℃,13 ℃,12 ℃,13 ℃,15 ℃,18 ℃,则这几天最高气温的众数是__13_℃__.14.已知样本中各数据与样本平均数的差的平方和是(x 1-x )2+(x 2-x )2+…+(x 10-x )2=40,则样本方差s 2=__4__.15.不等式组⎩⎪⎨⎪⎧x +1≥0,2x -9<0的所有整数解的中位数是__1.5__. 16.为了检测某自动包装流水线的生产情况,在流水线上随机抽取40件产品,分别称出它们的质量(单位:克)作为样本.如图是样本的频率分布直方图,根据图中各组的组中值估计产品的平均质量是__507__克.17.已知一组数据9,7,8,a ,4的众数是7,则这组数据的中位数是__7__.18.小明同学5次数学单元测试成绩(分数取整数)的平均分是90分,且每次测试都没有低于80分的成绩,中位数是93分,唯一众数是96分,则最低的一次成绩可能是__80或81或82__分.。
2020-2021学年 人教版八年级数学下册第十八章 平行四边形 常考填空题综合练习(一)
八年级数学人教版下册第十八章《平行四边形》常考填空题综合练习(一)1.Rt△ABC中,∠C=90°,点D是斜边AB的中点,若CD=2,则AB=.2.如图,在矩形ABCD中,线段DF平分∠ADC交BC边于点F,点E为BC边上一动点,连接AE,若在点E移动的过程中,点B关于AE所在直线的对称点有且只有一次落在线段DF上,则BC:AB=.3.如图,四边形ABCD是长方形,F是DA延长线上一点,CF交AB于点E,G是CF 上一点,且∠ACG=∠AGC,∠GAF=∠F.若∠ECB=20°,则∠ACD的度数是.4.如图,矩形ABCD中,AD=5,AB=7,正方形MBND′的顶点M,N分别在矩形的边AB,BC上,点E为DC上一个动点,当点D与点D′关于AE对称时,DE的长为.5.一个正方形的对角线长为2,则其面积为.6.一个菱形的面积为20cm2,它的两条对角线长分别为ycm,xcm,则y与x之间的函数关系式为y=.7.如图,点O是菱形ABCD对角线的交点,DE∥AC,CE∥BD,连接OE,设AC=12,BD=16,则OE的长为.8.如图,在菱形ABCD中,AC=6,AB=5,点E是直线AB、CD之间任意一点,连结AE、BE、DE、CE,则△EAB和△ECD的面积和等于.9.如图,在平面直角坐标系中,点A的坐标是(0,3),点B的坐标是(﹣4,0),以AB为边作正方形ABCD,连接OD,DB.则△DOB的面积是.10.如图,在△ABC中,AB=AC,BC=6,AF⊥BC于点F,BE⊥AC于点E,且点D 是AB的中点,△DEF的周长是11,则AB=.11.如图,四边形ABCD是正方形,△CBE是等边三角形,则∠AEB=.12.如图,在△ABC中,AB=AC,AD⊥BC,垂足为D,E是AC的中点.若DE=3,则AB的长为.13.著名画家达芬奇不仅画意超群,同时还是一个数学家,发明家.他曾经设计过一种圆规.如图所示,有两个互相垂直的滑槽(滑槽宽度忽略不计)一根没有弹性的木棒的两端A,B能在滑槽内自由滑动,将笔插入位于木棒中点P处的小孔中,随着木棒的滑动就可以画出一个圆来,若AB=10cm,则画出的圆半径为cm.14.如图所示,矩形ABCD的两条对角线相交于点O,∠AOB=60°,AB=2,则矩形的对角线AC的长是.15.已知正方形ABCD的边长为2,EF分别是边BC,CD上的两个动点,且满足BE=CF,连接AE,AF,则AE+AF的最小值为.16.如图所示,在边长为6的正方形ABCD外以CD为边作等腰直角△CDE,连接BE,交CD于点F,则CF=.17.如图,在矩形ABCD中,O为AC中点,EF过O点且EF⊥AC分别交DC于F,交AB于E,点G是AE中点且∠AOG=30°,则下列结论正确的是.(1)DC=3OG;(2)OG=BC;(3)△OGE是等边三角形;(4)S△AOE=.18.如图,Rt△ABC中,∠C=90°,AC=12,BC=5.分别以AB、AC、BC为边在AB的同侧作正方形ABDE、ACFG、BCIH,四块阴影部分的面积分别为S、S2、S3、1 S.则S1+S2+S3+S4等于.419.如图,平面直角坐标系中,四边形OABC为菱形,点A在x轴正半轴上,点A的坐标为(4,0),∠AOC=60°,对角线OB,AC相交于点E,则点E的坐标为.20.如图,正方形ABCD的A点和C点都在x轴的正半轴上,A点的坐标为(﹣1,0).将正方形ABCD以点B为旋转中心顺时针旋转120°,点D恰好落在y轴的正半轴上(D1点处),得到正方形A1B1C1D1,则D1点的坐标为.参考答案1.解:在Rt△ABC中,点D是斜边AB的中点,CD=2,∴AB=2CD=2×2=4,故答案为:4.2.:1.3.30°.4.或.5.2.6.y=.7.10.8.解:连接BD交AC于O,∵四边形ABCD是菱形,∴AC⊥BD,OA=AC=×6=3,∵AB=5,由勾股定理得:OB=4,∴BD=2OB=8,∵AB∥CD,∴△EAB和△ECD的高的和等于点C到直线AB的距离,∴△EAB和△ECD的面积和=×菱形ABCD的面积×==12.故答案为:129.解:过点D作DE⊥y轴,垂足为E.∵A的坐标是(0,3),点B的坐标是(﹣4,0),∴OA=3,OB=4.∵ABCD为正方形,∴AB=AD,∠DAB=90°.∴∠DAE=∠AB0.在△ABO和△DAE中,∴△ABO≌△DAE.∴AE=OB=4.∴OE=AE+AO=4+3=7.∴△OBD的面积=OB•OE=×4×7=14.故答案为:14.10.解:∵AF⊥BC,BE⊥AC,D是AB的中点,∴DE=DF=AB,∵AB=AC,AF⊥BC,∴点F是BC的中点,∴BF=FC=3,∵BE⊥AC,∴EF=BC=3,∴△DEF的周长=DE+DF+EF=AB+3=11,∴AB=8,故答案为:8.11.解:∵四边形ABCD是正方形,△CBE是等边三角形,∴AB=BC,∠BAD=90°,BE=BC,∠CBE=60°,∴AB=BE,∠ABE=90°﹣60°=30°,∴∠AEB=∠EAB=(180°﹣30°)=75°,故答案为:75°.12.解:∵在△ABC中,AD⊥BC,垂足为D,∴△ADC是直角三角形;∵E是AC的中点.∴DE=AC(直角三角形的斜边上的中线是斜边的一半),又∵DE=3,AB=AC,∴AB=6,故答案为:6.13.解:如图,∵两个滑槽互相垂直,点P是木棒的中点,∴OP=AB=×10=5cm,即画出的圆半径为5cm.故答案为:5.14.解:∵四边形ABCD是矩形,∴AC=2AO,BD=2BO,AC=BD,∴AO=OB,∵∠AOB=60°,∴△AOB是等边三角形,∴AB=AO=2,即AC=2AO=4,故答案为:4.15.2.16.2.17.(1)(3)(4).18.解:过D作BM的垂线交BM于N,∵图中S2=S Rt△DOI,S△BOC=S△MND,∴S2+S4=S Rt△ABC.∵四边形ABDE、ACFG、BCIH均为正方形,∴AE=AB,AG=AC,∠G=∠ACB=90°,BC=HI,∴在Rt△AGE与Rt△ACB中,,∴Rt△AGE≌Rt△ACB(HL),在Rt△DNB与Rt△BHD中,,∴Rt△DNB≌Rt△BHD,∴S1+S2+S3+S4=S1+S3+(S2+S4),=Rt△ABC的面积+Rt△ABC的面积+Rt△ABC的面积=Rt△ABC的面积×3=12×5÷2×3=90.故答案为:90.19.解:过点E作EF⊥OA,垂足为F,∵四边形OABC为菱形,∠AOC=60°,∴∠EOA=∠AOC=30°,∠OEA=90°,∵点A的坐标为(4,0),∴AO=4,则AE=OA=2,故OE===2,∴AO•EF=AE•OE,则4EF=2×2,解得:EF=,则OF===3,故点E的坐标为(3,).故答案为:(3,).20.(0,2).。
人教版八年级英语下册综合填空与阅读表达专题练习
八下题型专练——综合填空与阅读表达综合填空A 选择单词的适当形式填空(一)1.We will have a good time _______in the countryside.2. I found my sister ___________my things yesterday.3. While Linda was sleeping, Jenny _________Mary with her homework.4. You _______ your homework at home.5. He expected most or all of the passengers_________ and wait for the next bus.6. As a result, he often______ ill and his grades dropped.7. As a mountain climber, Aron is used to ________.8. When they argue, it’s like a big, black cloud __________ our home.9. I don’t mind you__________, but you’d better give it up.(二)1. He now has sixteen bikes________ and give away to children who don’t have bikes.2. Could I are least finish ________this show?3. Since they live in one house with their parents, they should know that everyone should do their part in ________it clean and tidy.4. It is the parents’job__________ a clean and comfortable environment at home for their children.5. I was in the kitchen ________my mom.6. It was hard to have fun with a serious storm ________outside.7. I _______the floor just now, but it is dirty again.(三)1.Jane can’t go to your birthday party because she is going to ______tomorrow.2. ________have a healthy body, Jenny does a lot of exercise..3. Jim ________ two hours ________ TV last night.4. Could you ________the ________ the cleaning?5. In the past I _________ my parents too much.6. Can you _________your sister while your parents are out?(四)football skill develop continue compare train1. The company (公司) needs lots of workers with ___________.2. He isn’t good at swimming. He needs lots of ___________.3. My favorite sport is ___________.4. It’s important for our country ___________ developing low-carbon economy (低碳经济).5. Many foreigners are surprised at the rapid (快速的) ___________ of China.6. After ___________ the two companies carefully, he decided to work in the bigger one.B根据汉语及首字母填单词(一)1.There will be more_____________(乘客) on the bus.2.You can give away the things that you won’t use, or take after the _____________(病的) people at the hospital.3.My cousin borrowed my book without________(归还)it.4. The old man felt very _______(孤独) after his dog died.5. Mr. White ate something bad and had a _________(胃痛) last night.(二)1.After a long walk ,I really wanted to ________(躺下) down and relax myself.2.I’m sorry to keep you _________(等待)me for a long time.3.Can you _________(猜测;估计)who will come to the party?4.My mother likes to say “that’s a _______(协议;交易).5.Do you think it is hard to _______(交流;沟通) with your parents?(三)1.Don’t _______(抄袭)other’s homework .It’s bad for yourstudy.2.Can you ________(解释) Why you are late for class?\3. The ________(死)of Steve Jobs made millions of Apple fans sad.4.I’m new here so I have ________(困难)in getting on well with others.5.Jack’s dog is much_______(聪明的)than mine.(四)1.Kids these days already have enough_______(压力)from school.2.It is the parents’job to ________(提供) a clean and comfortable environment at home for their children.3.Doing chores helps to develop children’s _______(独立性)and teaches them how to look after themselves.4.As a result ,he often fell ill and his grades _______(下降)5.I get such a strong feeling of _______(满足)when I see the animals get better and the look of joy on their owners’faces.C选择恰当的词或短语填空,(有两项多余选项)(一)Dear Mr. Hunt,My problem is that I can’t get on with my family. 1 between my parents have become difficult. They fight a lot, and I really don't like it. It's the only communication they have.I don't know if I should say anything to them about this. When they argue, it's like a big, black cloud hanging 2 our home. Also, my elder brother is not very nice to me. He always refuses to let me watch my favorite TV show. 3 he watches whatever he wants 4 late at night. I don't think this is fair. At home I always feel 5 and nervous. Is that normal? What can I do?Sad and ThirteenDear Sad and Thirteen,It's not easy being your age, and it's normal to have these feelings. Why don't you talkabout these feelings with your family? If your parents are having problems, you should 6 to help. 7 you could do more jobs around the house 8 they have more time for proper communication. Secondly, why don't you sitdown and communicate 9 your brother? You should explain that you don't 10 him watching TV all the time. However, he should let you watch your favorite show. I hope things will be better for you soon.Robert Hunt(二)Most people in the U.S. speak only one language, English. They do not learn to speak a second___1___. Languages are taught in high schools, but very few students learn to speak well. Why don’Americans speak ___2___ languages?First, most Americans never travel to other countries. The United States is a very ___3___ country. Americans can travel a long distance and don’t leave the United States. They do not need to learn ___4___ second language.Second, one of the countries ___5___ the United States is Canada. Most people in Canada speak English. Some Americans live near Canada. They travel there often. ___6___ they do not have to learn a new language.Third, many people in other parts of the world speak English. If Americans travel to other countries, they can speakEnglish there, ___7___.Some Americans think that it is a mistake to speak ___8___ English. They believe it is very important to learn a second language. Maybe ___9___ other Americans will agree. Then ___10___ people will speak a second language in the United States.(三)expected, thinking, himself, quickly, thought, lying, shouting, should, for, surpriseAt 9:00 a.m. yesterday, bus No. 26 was going along Zhonghua Road when the driver saw an old man 1 on the side of the road. A woman next to him was 2 for help.The bus driver, 24-year-old Wang Ping, stopped the bus without 3 twice. He got off and asked the woman what happened. She said that the man had a heart problem and 4 go to the hospital. Mr. Wang knew he had to act 5 . He told the passengers that he must take the man to the hospital. He 6 most or all of the passengers to get off and wait 7 the next bus.But to his 8 , they all agreed to go with him. Some passengers helped Mr. Wang to move the man on the bus.Thanks to Mr. Wang and the passengers, the doctorssaved the man in time. "It'ssad that many people don't want to help others because they don’t want any trouble," says one passenger. "But the driver didn't think about 9 . He only 10 about saving a life."(四)Dear Sir,I think it is important for children to learn _______ to do chores and help their parents ________ housework. It’s not enough to just get good grades at school. Children these days _______ on their parents too much. They’re always________, “Could you get this for me?”or “Could you help me with that?”_______ chores helps to develop children’s independence and teaches them how to look after________. It also helps them to understand the idea of fairness. Since they live in one house with their parents, they should know that everyone should do their part _______ keeping it clean and tidy. Our neighbor’s songot into a good college but during his first year, he had no idea how to ________ himself. As a result, he often fell ill and his grades______. The ________ kids learn to be independent, the better it is for their future.Ms. Miller(五)Running is free, easy and now it's also becoming cool. Many people do not have enough time to play a team sport, so they start running 11 . In the past, people thought running in the street was a little funny, but now things are different---it is becoming 12 . Lots of people choose to run in the streets 13 their free time 14 it is a simple way to 15 healthy. Some of them even begin each day 16 a morning run. For them, it’s like a fresh start.Every year in the April, London hosts the London Marathon (马拉松). The race covers a fantastic route(路线), and runners can forget the beauty of London 17 running. People fromall over the world join the London Marathon. In the past, people saw marathon running as a professional(专业的)18 , but now even common people are doing it. It’s not because marathon is becoming 19 ; it’s because people are becoming more and more interested in running. And they want to try it 20 .All you need is a pair of running shoes, so what are you waiting for? Startrunning tomorrow.任务性阅读:AOne day an Australian farmer, Joe, saw a bright light in the sky. ①The light came nearer and nearer and suddenly Joe saw that it was a spaceship. The spaceship landed in a field quickly. The door of the spaceship opened and two strange beings climbed out.②They seemed to be half man and half bird.Joe was afraid of them. He tried to run away. But the spacemen walked towards him, picked him up and carried him into the spaceship. They put wires(电线) from a machine ontohis head and they could speak to him in English. They asked him some questions about the earth. "We are from Venus," they said, "but it's getting very hot there. A lot of our people are dying and we don't have much time left. We are trying to find a new home."After some time they③freed Joe and at last the spaceship took off and could not be seen again. Joe told his friends about the spaceship, but no one believed his story. "You'll believe me one day," Joe told them. "The spaceman will come back..."1.翻译①处画线部分句子_______________________________.2.2. 不改变句意,改写②处句子_______________________________.3. What do we know about Venus? __________________________.3.4. ③处单词的意思是_____A. let…goB. paid no moneyC. took awayD. locked5. 用文中的两个词填空。
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1. 平行四边形ABCD 的周长为20cm ,对角线AC 、BD 相交于点O ,若△BOC 的周长比△AOB 的周长大2cm ,则CD = cm .
2.在直角三角形ABC 中,∠C =90°,CD 是AB 边上的中线,∠A =30°,AC =53,则△ADC 的周长为 _____.
3.如图,平行四边形ABCD 的两条对角线AC 、BD 相交于 点O ,AB = 5,AC =6,DB =8则四边形ABCD 的周长为 .
4.在矩形ABCD 中,对角线AC 、BD 相交于点O ,若∠AOB =60°,AC
5.某公司欲招聘工人,对候选人进行三项测试:语言、创新、综合识,并按测试得分1:4:3的比例确定测试总分,已知三项得分分别为88,72,50,则这位候选人的招聘得分为________;
6.如图,已知OA =OB ,那么数轴上点A 所表示的数是_____.
7.已知菱形ABCD 的两条对角线AC 与BD 相交于点O ,AC =10cm ,BD =16cm ,则菱形ABCD 的面积是 .
8.如果直线x y -=向上平移3个单位后得到直线AB ,那么直线AB 的解析式是_________. 9.如图,Rt △ABC 中,∠BAC =90°,D ,E ,F 分别为AB
,BC , AC 的中点,已知DF =3,则AE = .
10.如图,直线1l :1y x =+与直线2l :y mx n =+相交于点P (a ,2), 则关于x 的不等式1x +≥mx n +的解集为
. 11.若m ≥3,化简_____)3(2=-m
12.在三角形ABC 中,AB =AC =5,BC =6,若点P 在边AC 上移动,则BP 的最小值是_________. 13.若数据8,9,7,8,x ,3的平均数是7,则这组数据的众数是 . 14.设1
a ,则代数式2212a a +-的值为 15如图,长方形ABCD 中,AB =8,BC =4,将长方形沿AC 折叠, 点D 落在D /
处,则重叠部分△AFC 的面积为 . 16.我市5月份某一周最高气温统计如下表: 则这组数据的中位数是____,平均数是___. 17.在函数2
y x =-中,自变量x 的取值范
围是_______.
b
3
ax-
A B
C
D
E
F
18.如图4,将△ABC纸片折叠,使点A落在边BC上,记落点为点D,且折痕EF∥BC,若BC=4,则EF的长度为________________.
19. 如图5,已知一次函数y=kx+b的图象,当y >1时,x的取值范围是______.
20.关于x的一元二次方程2(21)10
mx m x m
+-++=有实数根,则m的取值范围是_______.
21.直线
4
4
3
y x
=+与x轴、y轴分别交于点A和点B,在x轴上取点C,使△ABC为等腰三角形,则点C的坐标是_________________.
22.若二次根式x5
2+有意义,则x的取值范围为.
23.计算0)2
(
2
1
8+
⨯的结果是.
24.当x= 时,最简二次根式5
3+
x与7
2
2+
x能够合并.
25.三角形的两边长分别为3和5,要使这个三角形是直角三角形,则第三边长是.
26.数据﹣2,﹣1,0,3,5的方差是________.
27.如图,平行四边形ABCD中,
∠ABC=60°,E、F分别在CD和BC的延长线上,AE∥BD,EF⊥BC,EF=,则AB的长是.
28.如图,已知函数
1
3
y x b
=+和
2
3
y ax
=-的图象交于点(2,5)
P--,则不等式33
x b ax
+>-
的解集为
29.如图,在ABCD
Y中, E,F分别为边,BD.
(1)求证:ADE CBF
△≌△.
(2)若AD BD
⊥,则四边形BFDE是什么特殊四边形?请证明你的结论.。