初一第四次周测
初一数学试题大全

初一数学试题答案及解析1.(本题8分)如图,已知在四边形ABCD中,∠B=∠D=,AE、CF分别是∠DAB及∠DCB的平分线.则AE与FC有什么关系?请说明理由。
【答案】AE∥CF 2分由四边形的内角和推出∠DAB与∠DCB互补 1分由角平分线推出∠DAE与∠DCF互余 2分再由∠DFC与∠DCF互余推出∠DFC=∠DAE 2分所以AE∥CF 1分【解析】略2.某种细菌在培养过程中,每半小时分裂1次,每次一分为二.若这种细菌由1个分裂到32个,那么这个过程要经过( )A.2小时B.2.5小时C.3小时D.8小时【答案】B【解析】略3.(本题8分)已知有理数满足①;②是一个三次单项式且系数为-1:(1)求的值; (2)求代数式的值.【答案】解:(1)依题意得:(每个结果各1分)(2)由(1)得∴∴·······1分∴原式=······3分【解析】略4.在中,负数有,分数有 .【答案】【解析】大于0的数为正数,小于0的数为负数5.“x与y的和大于1”用不等式表示为.【答案】x+y>1【解析】根据关键词得到两个数的和与1的关系是解决本题的关键.x与y的和可表示为:x+y,“x 与y的和大于1”用不等式表示为:x+y>1,【考点】由实际问题抽象出一元一次不等式6.(10分)因式分解:(1)ax4﹣ay4(2)﹣4x2+12xy﹣9y2.【答案】﹣(2x﹣3y)2.【解析】(1)先提取公因式a,再对余下的多项式利用平方差公式继续分解;(2)先提取公因式a,再根据完全平方公式进行二次分解.完全平方公式:a2﹣2ab+b2=(a﹣b)2.试题解析:(1)ax4﹣ay4=a(x4﹣y4)=a(x2+y2)(x2﹣y2)=a(x2+y2)(x+y)(x﹣y);(2)﹣4x2+12xy﹣9y2=﹣(4x2﹣12xy+9y2)=﹣(2x﹣3y)2.【考点】提公因式法与公式法的综合运用.7.有理数a、b在数轴上对应的位置如图所示,则()A.a+b<0B.a+b>0C.a-b=0D.a-b>0【答案】A【解析】根据数轴可得:a<0,b>0,,则a+b<0,a-b<0.【考点】数轴、有理数计算8.如果-是7次单项式,则n的值为.【答案】3.【解析】试题解析:∵-是7次单项式,∴2n+1=7,解得:n=3.【考点】单项式.9.已知有理数a、b在数轴上对应点的位置如图所示,且|a|>|b|,则|a|-|a+b|-|b-a|的值为()A.2b+a B.2b-a C.a D.b【答案】C【解析】由数轴可以看出,且,则故选C.【考点】1、数轴;2、绝对值.10.(2014秋•桐乡市期中)已知代数式2y2+3y的值为8,则代数式4y2+6y﹣9的值为.【答案】7【解析】原式前两项提取2变形后,将2y2+3y的值代入计算即可求出值.解:∵2y2+3y=8,∴原式=2(2y2+3y)﹣9=16﹣9=7.故答案为:7.【考点】代数式求值.11.用一个正方形在四月份的日历上,圈出4个数,这四个数的和不可能是()A.104B.108C.24D.28【答案】B【解析】先设最小的数是x,则其余的三个数分别是x+1,x+7,x+8,求出它们的和,再把A、B、C、D中的四个值代入,若算出的x是正整数,则符合题意,否则就不合题意.解:设最小的代数式是x,则其它三个数分别是x+1,x+7,x+8,四数之和=x+x+1+x+7+x+8=4x+16.A、根据题意得4x+16=104,解得x=22,正确;B、根据题意得4x+16=108,解得x=23,而x+8=31,因为四月份只有30天,不合实际意义,故不正确;C、根据题意得4x+16=24,解得x=2,正确;D、根据题意得4x+16=28,解得x=3,正确.故选B.【考点】列代数式.12.如图,已知点O在线段AB上,点C、D分别是AO、BO的中点(1)AO= CO;BO= DO;(2)若CO=3cm,DO=2cm,求线段AB的长度;(3)若线段AB=10,小明很轻松地求得CD=5.他在反思过程中突发奇想:若点O在线段AB的延长线上,原有的结论“CD=5”是否仍然成立呢?请帮小明画出图形分析,并说明理由.【答案】(1)2;2;(2)AB=10cm;(3)成立,理由见解析.【解析】(1)根据中点的性质得出答案;(2)根据(1)的结论进行求解;(3)画出图形,然后进行求解.试题解析:(1)根据题意可得:AO=2CO;BO=2DO(2)根据(1)的结论可得:AO=6cm;BO=4cm,则AB=AO+BO=6+4=10cm(3)任然成立.理由如下:如图所示:根据题意得:CO=AO,DO=BO∴CD=CO-DO=AO-BO=(AO-BO)=AB=×10=5cm.【考点】线段中点的性质.13.如图,∠ABD和∠BDC的平分线交于点E,BE的延长线交CD于点F,且∠1 +∠2 = 90°.猜想∠2 与∠3的关系并证明.【答案】∠2+∠3=90°.证明见解析.【解析】根据角平分线定义得出∠ABF=∠1,∠ABD=2∠1,∠BDC=2∠2,求出∠ABF+∠2=90°,∠ABD+∠BDC=180°,根据平行线的判定得出AB∥DC,根据平行线的性质得出∠3=∠ABF,即可得出答案.试题解析:∵∠ABD和∠BDC的平分线交于点E,∴∠ABF=∠1,∠ABD=2∠1,∠BDC=2∠2,∵∠1+∠2=90°,∴∠ABF+∠2=90°,∠ABD+∠BDC=2×90°=180°,∴AB∥DC,∴∠3=∠ABF,∴∠2+∠3=90°.【考点】平行线的判定与性质.14.如图所示,长方形ABCD是“阳光小区”内一块空地,已知AB=2a,BC=3b,且E为AB边的中点,CF=BC,现打算在阴影部分种植一片草坪,求这片草坪的面积。
4.勤学早七年级数学(上)第1章《有理数》周测(四)

4勤学早七年级数学(上)第1章《有理数》周测(四)(测试范围:1.5有理数的乘方 科学记数法 解答参考时间:90分钟 满分120分)一、选择题(每小题3分,共30分)1. ...n aa a a a ⋅⋅个记作( A )A . n aB .n +aC .naD .a n2.(-1)2018的值是( A )A .1B .-1C .2018D .- 20183.宁波舟山港45万吨原油码头成功挂靠全球最大油轮——“泰欧’轮,其中45万吨用科学记数法表示为( B )A .0.45×106吨B .4.5×105吨C .45×104吨D .4.5×104吨4.计算|-1|-(-1)3的结果是( D )A . -2B .-1C .0D .25.由四舍五入法得到的近似数1. 28×104,下列说法中正确的是( C )A .精确到十位B .精确到个位C .精确到百位D .精确到百分位6.下列算式正确的是( B )A .(- 23)2 = 43B .-23=-8C .-32 =-3×(-3)=9D .23 =2×3=6 7.小刚学习了有理数运算法则后,编了一个计算程序.当他输入任意一个有理数时,显示屏上出现的结果总等于所输入的有理数的平方与1的和,当他第一次输入-1,然后又将所得的结果再次输入后,显 示屏上出现的结果应是( B )A .-8B .5C .-24D .268.(2018浦东)下面各对数中,结果相等的是( C )A . -32和(-3)2B .-(-3)2和-(2)3C .-(-3)2和- 32D .-2×32和-3×229.(2018海淀)观察下列等式:31=3,32=9,33=27,34 =81,35 =243,36 =729,…,通过观察,用你所发现的规律确定32018的个位数字是 ( B )A. 3B. 9C. 7D. 110.(2018昆明)下列说法:①若a 为有理数, 且a ≠0,则a <a 2;②若1a a=,则a =1;③若a 3+ b 3=0,则n ,6互为相反数;④若|a |=-a ,则a < 0;⑤若b <0<a ,且|a |<|b |,则|a +b |=-|a |+|b |,其中正确说法的个数是( B )个.A .1B .2C .3D .4二、填空题(每小题3分,共18分)11.(2018官渡)计算:(-1)2+(-1)3的结果为 0.12.已知(a -3)2+lb +2| =0,则b a 的值是 -8.13.(2018临沂)用“☆”,“★”定义新运算:对于任意有理数a ,b ,都有a ☆ b =a b 和a ★b =b a ,那么(-3☆2)★1=1.14.如图,是一个有理数运算程序的流程图,请根据这个程序回答问题,当输入的x 为-2时,最后输出的结果y 是74 . 15.(2018衡水)现有一根长为1米的木杆,第1次截取其长度的一半,第 2次截取其第1次剩下长度的一半,第3次截取其第2次剩下长度的;一半,如此反复截取,则第n (n 为正整数)次截取后,此木杆剩下的长1 2n ⎛⎫⎪⎝⎭16.(2018珠海)我们常用的数是十进制数,计算机程序使用的是二进制;数(只有数码0和1),它们两者之间可以互相换算,如将(101)2,;(1011)2换算成十进制数应为:(101)2=1×22+0×21+1=4+0+1=5,(1011)2=1×23+0×22+1×21+1=11.按此方式,将二进制(10101)2换算成十进制数的结果是21三、解答题(共8题,共72分)17.(8分)计算:(-10)2-(-3×2)2+(-2)3×10.解:原式=-1618.(8分)计算:-32-[0.2÷45×(-2)2].解:原式=-1019.(8分)已知a=-3,b=2,c=-1,求下列代数式的值(1)a2+b2-C2;(2) (a-b-c)2.解:(1)原式=12; (2)原式=16.20.(8分)若x与y互为相反数,m与n互为倒数,|a|=2,求a2-(x+y) 2017+(-mn) 2018的值.解:原式=521.(8分)已知a2=9,|b|=4.(1)若ab>0,求a+b的值;(2)若|a-b|=b-a,求ab的值解:(1)±7 (2)a<b, ∴a=±3,b=4,ab=±1222. (10分)阅读材料,求值:1+2+22+23+24+ (22017)解:设S=1+2+22+23+24+…+211,将等式两边同时乘以2得:2S=2+22+23+24+...+22015+22018将下式减去上式得2S-S=22018-1即S=1+2+22+23+24+...+22017=22018-1请你仿照此法计算:(1)1+2+22+23+ (210)(2)1+3+32+33+34+…+3n(其中n为正整数).解:(1)211-1;(2).1 312n+-23.(10分)观察下面三行数:2,-4,8,-16,32,-64,……①0,-6,6,-18,30,-66,……②2,-10,14,-34,62,-130.……③(1)第①行第7个数为128,第②行第7个数为126,第③行第7个数为254;(2)用含n的式子表示第①②③行中第n个数;(3)第1列的3个数之和为4,第二列3个数之和为-20,是否存在这样的一列数,这列数中的三个数之和为1020?若存在,请说明是哪三个数;若不存在,说明理由.解:(1)128,126,254;(2)第①行第n个数为(-1)n+1·2n,第②行第n个数为(-1)n+1·2n-2,第③行第n个数为(-1)n+1×2n×2-2;(3)设第①行中的数为x,则另外两个数分别为x-2,x+x-2,∴x+x-2+x+x-2=1020,x=256,∵第①行第8个数为-256,∴不存在.24.(12分)有理数a,b,c在数轴上的位置如图.(1)请直接指出a,|b|,c的大小关系(用“<”连接);(2)若m=||||||+a b ca b c,求1-2018m3的值;(3)若a=-2,b=-3,c=23,且a,b,c对应的点分别为A,B,C,点P是数轴上的一动点,设点P表示的数为x,若P与A的距离是P与C的距离的3倍,求x的值.解:(1)a<c<|b|;(2)由图可知:b<a<0<c<1,∴m=-1,∴1-2018m3=1-2018×(-1)3=2019;(3)当P在A,C之间时,PA=x+2,PC=23-x, ∵PA=3PC, ∴x+2=3(23-x),x=0;当P在C点右侧时,PA=x+2,PC=x-23,∵PA-3PC.∴x+2=3 (x-23),x=2.综上所述,x的值为0或2.。
人教版数学七年级下册第五章《相交线与平行线》周练习含答案

人教版数学七年级下册第五章《相交线与平行线》周练习第五章相交线与平行线周周测1一选择题1. 如图:下列四个判断中,正确的个数是().①的内错角只有②的同位角是③的同旁内角是..④图中的同位角共有个A. 个B. 个C. 个D. 个2.如图,已知于点,点..在同一直线上,且,则为().A.B.C.D.3.如图,直线相交于点 ,射线平分 , ,若,则的度数为().A.B.C.D.4.如图,直线.被直线所截,则的同旁内角是()A.B.C.D.5.如图,与是内错角的是()A.B.C.D.6.如图,与是()A. 对顶角B. 同位角C. 内错角D. 同旁内角7.已知两条平行线被第三条直线所截,则以下说法不正确的是()A. 一对同位角的平分线互相平行B. 一对内错角的平分线互相平行C. 一对同旁内角的平分线互相平行D. 一对同旁内角的平分线互相垂直8.如图,直线相交于点,于,若,则不正确的结论是()A.B.C.D.9.如果点在直线上,也在直线上,但不在直线上,且直线..两两相交符合以上条件的图形是()A.B.C.D.10.如图两条非平行的直线被第三条直线所截,交点为,那么这条直线将所在平面分成()A. 个部分B. 个部分C. 个部分D. 个部分11.如图,若两条平行线,与直线,相交,则图中共有同旁内角的对数为()A.B.C.D.12.若点到直线的距离为,点到直线的距离为,则线段的长度为()A.B.C. 或D. 至少13.如图,在平面内,两条直线,相交于点,对于平面内任意一点,若,分别是点到直线,的距离,则称为点的“距离坐标”.根据上述规定,“距离坐标”是的点共有()个.A. 个B. 个C. 个D. 个14.如图,两条直线,交于点,射线是的平分线,若,则等于()A.B.C.D.15.如图,点是直线外的一点,点在直线上,且,垂足是,,则下列不正确的语句是()A. 线段的长是点到直线的距离B. 线段的长是点到直线的距离C. 三条线段中,最短D. 线段的长是点到直线的距离二填空题16.如图,与相交于点,,,则度.17.如图,在菱形中,点是对角线上的点,于点,若,则到的距离为.18.如图,标有角号的个角中共有对内错角,对同位角,对同旁内角.19.四条直线两两相交,至多会有个交点.20.如图,,,,则度.三解答题21.如图,图中共有多少对同位角,多少对内错角,多少对同旁内角.22.如图,用数字标出的八个角中,同位角.内错角.同旁内角分别有哪些?请把它们一一写出来.23.如图,直线..两两相交,射线平分,已知,,求的度数.第五章相交线与平行线周周测1 参考答案与解析一、选择题1.C2.B3.C4.C5.D6.B7.C8.C9.D 10.C 11.D 12.D13.D 解析:依题意,作与l1平行且距离为2的直线两条,作与l2平行且距离为1的直线两条,两组平行线的交点即为所求,共4个点符合题意.14.C 15.B二、填空题16.36 17.3 18.4 2 4 19.6 20.55三、解答题21.解:有6对同位角,4对内错角,4对同旁内角.22.解:同位角:∠2与∠8,∠3与∠7,∠4与∠6;内错角:∠1与∠4,∠2与∠6,∠3与∠5,∠4与∠8,;同旁内角:∠2与∠4,∠2与∠5,∠3与∠6,∠4与∠5.23.解:∵BE平分∠ABD,∠2=75°,∴∠ABE=∠2=75°,∴∠1=180°-∠ABE=∠2=180°-75°-75°=30°.∵∠1=3∠3,∴∠3=25°.∵∠3与∠4是对顶角,∴∠4=∠3=25°.第五章相交线与平行线周周测2一选择题1.如图,已知直线a,b被直线所截,那么的同位角是()A.B.C.D.2. 如图,已知三条直线,,相交于一点,则等于().A. °B. °C. °D. °3.将一副三角板按图中方式叠放,则角的度数是().A.B.C.D.4.如图,下列叙述正确的是().A. 和是内错角B. 和是同位角C. 和是同位角D. 和是同旁内角5.如图,直线,被直线所截,则的同旁内角是()A.B.C.D.6.如图:下列四个判断中,正确的个数是().①的内错角只有②的同位角是③的同旁内角是,,④图中的同位角共有个A. 个B. 个C. 个D. 个7.甲.乙.丙.丁四个学生在判断时钟的分针与时针互相垂直的时,他们每个人都说两个时间,说对的是()A. 丁说时整和时整B. 丙说时整和时分C. 乙说点分和点分D. 甲说时整和点分8.如图,直线相交于点,于,若,则不正确的结论是()A.B.C.D.9.如图,若两条平行线,与直线,相交,则图中共有内错角的对数为()A.B.C.D.10.如图,能表示点到直线的距离的线段共有()A. 条B. 条C. 条D. 条11.在一个平面上任意画条直线,最多可以把平面分成的部分是()A.B.C.D.12.如图,点是直线外的一点,点在直线上,且,垂足是,,则下列不正确的语句是()A. 线段的长是点到直线的距离B. 线段的长是点到直线的距离C. 三条线段中,最短D. 线段的长是点到直线的距离二填空题13.如图,与相交于点,,,则度.14.如图,,于,图中共有_______个直角,图中线段______的长表示点到的距离,线段_________的长表示点到的距离.15.如图,的内错角有个.16.如图,,,,则度.三解答题17.如图,图中共有多少对同位角,多少对内错角,多少对同旁内角.18.如图,用数字标出的八个角中,同位角.内错角.同旁内角分别有哪些?请把它们一一写出来.19.如图,直线,,相交于点,平分,,.求的度数.第五章相交线与平行线周周测2 参考答案与解析一、选择题1.A2.C3.D4.A5.C6.C7.A8.C9.D 10.D 11.C 12.B二、填空题13.36 14.3 CD AC 15.3 16.55三、解答题17.解:有6对同位角,4对内错角,4对同旁内角.18.解:同位角:∠2与∠8,∠3与∠7,∠4与∠6;内错角:∠1与∠4,∠2与∠6,∠3与∠5,∠4与∠8,;同旁内角:∠2与∠4,∠2与∠5,∠3与∠6,∠4与∠5.19.解:∵,,∴∠DOE=180°-∠1-∠2=180°-30°-45°=105°.∵∠DOE与∠COF是对顶角,∴∠COF=105°.∵平分,∴∠3=∠FOG=105°÷2=52.5°.第五章相交线与平行线周周测3一选择题1. 如图,已知∠1=∠2,则下列结论一定成立的是()A.AB//CD B.AD//BC C.∠B=∠D D.∠3=∠42. 下列图形中,能由∠1=∠2得到AB//CD的是()A.B. C.D.3. 如图,能判定的条件是()A.B.C.D.4. 对于图中标记的各角,下列条件能推理得到a∥b的是()A.∠1=∠2 B.∠2=∠4 C.∠3=∠4 D.∠1+∠4=180°5. 如图,下列条件中:(1)∠B+∠BCD=180°;(2)∠1=∠2;(3)∠3=∠4;(4)∠B=∠5.能判定AB∥CD的条件个数有()A.1个B.2个C.3个D.4个6. 如图,下列条件中,不能判断直线∥的是()A.∠1=∠3 B.∠2=∠3 C.∠4=∠5 D.∠2+∠4=180°7. 如图,已知∠1=70°,要使AB∥CD,则须具备另一个条件()A.∠2=70° B.∠2=100° C.∠2=110° D.∠3=110°8. 如图,用两个相同的三角板按照如图方式作平行线,能解释其中道理的定理是()A.同位角相等两直线平行B.同旁内角互补,两直线平行C.内错角相等两直线平行D.平行于同一条直线的两直线平行9. 如图,能判定EC∥AB的条件是()A.∠B=∠ACE B.∠A+∠ACD=180°C.∠ACE=∠DCE D.∠A=∠ACE10. 如图,下列能判定AB∥CD的条件有().(1)∠B+∠BCD=180°;(2)∠1=∠2;(3)∠3=∠4;(4)∠B=∠5.A.1个B.2个C.3个D.4个11. 过一点画已知直线的平行线,则( )A.有且只有一条B.有两条C.不存在D.不存在或只有一条12. 如图,能判断直线AB∥CD的条件是()A.∠1=∠2 B.∠3=∠4 C.∠1+∠3=180 o D.∠3+∠4=180 o二填空题13. 如图,两直线a.b被第三条直线c所截,若∠1=50°,∠2=130°,则直线a.b的位置关系是____________ .14. 在同一平面内,_____________________叫作平行线.15. 如图,直线a、b被直线c所截,若满足,则a、b平行(写出一个即可).16. 已知为平面内三条不同直线,若,,则与的位置关系是.三解答题17. 看图填空:如图,∠1的同位角是,∠1的内错角是,如果∠1=∠BCD,那么,根据是;如果∠ACD=∠EGF,那么,根据是.18. 如图,已知∠1=∠2,AC平分∠DAB,试说明DC∥AB.19.已知:如图,∠A=∠F,∠C=∠D.求证:BD∥CE.20.如图,已知:∠B=∠D+∠E,试说明:AB∥CD.第五章相交线与平行线周周测3 参考答案与解析一、选择题1.B2.D3.D4.D5.C6.B7.C8.C9.D 10. C 11.D 12.D二、填空题13.平行14.不相交的两条直线15.∠1=∠2(答案不唯一)16.平行三、解答题17.∠EFG ∠BCD,∠AED DE∥BC 内错角相等,两直线平行CD∥GF 同位角相等,两直线平行18. 解:∵AC平分∠DAB,,∴∠1=∠CAB.∵∠1=∠2,∴∠CAB=∠2,∴DC∥AB.19. 证明:∵∠A=∠F,∴AC∥DF,∴∠C=∠CEF.∵∠C=∠D,∴∠D=∠CEF,∴BD∥CE.20..解:过点E向右作EM//CD,则∠D=∠DEM.∵∠B=∠D+∠E,第五章相交线与平行线周周测4一选择题1.如图,是我们学过的用直尺和三角尺画平行线的方法示意图,画图的原理是()A.同位角相等,两直线平行B.内错角相等,两直线平行C.两直线平行,同位角相等D.两直线平行,内错角相等12第1题图第2题图第3题图2.如图,梯子的各条横档互相平行,若∠1=70°,则∠2的度数是()A.80°B.110°C.120°D.140°3.如图所示,点E 在AC 的延长线上,下列条件中能判断AB ∥CD 的是( ) A .∠3=∠4B .∠1=∠2C .∠D =∠DCE D .∠D +∠ACD =180°4.一辆汽车在笔直的公路上行驶,两次拐弯后,仍在原来的方向上平行前进,那么两次拐弯的角度是( )A .第一次右拐50°,第二次左拐130°B .第一次左拐50°,第二次右拐130°C .第一次左拐50°,第二次左拐130°D .第一次右拐50°,第二次左拐50° 5.如图,下列说法中,正确的是( ) A .因为∠A +∠D =180°,所以AD ∥BC B .因为∠C +∠D =180°,所以AB ∥CD C .因为∠A +∠D =180°,所以AB ∥CDD .因为∠A +∠C =180°,所以AB ∥CD 第5题图 二 填空题6.在同一平面内,如果直线b 和c 都与直线a 垂直,那么直线b 和c的位置关系是 . 7.如图,已知∠1=∠2,由此可得 ∥ .第7题图 第8题图8.如图,已知直线、被直线所截,∠1=60°, 则当∠2= °时,∥. 9.如图,小明利用两块相同的三角板,分别在三角板的边缘画直线和,这是根据________________,两直线平行.第9题图 第10题图10.如图,直线a 、b 与直线c 相交,给出下列条件:①∠1=∠2; ②∠4=∠6; ③∠4+∠7=180°; ④∠5+∠3=180°.其中能判断a ∥b 的条件是 (只填序号). 三 解答题11.如图,已知∠1=70°,∠2=110°,请用三种方法判定AB ∥DE.a b c a b AB CD12.已知:如图,CE平分∠ACD,∠1=∠2.求证:AB∥CD.第五章相交线与平行线周周测4 参考答案与解析一、选择题1.A2.B3.B4.D5.C二、填空题6.平行7.AD BC8.1209.内错角相等10.①③④三、解答题11. 解:(1)∵∠1=70°,∴∠AFC=180°-70°=110°.∵∠2=110°,∴∠AFC=∠2,∴AB//DE.(2)∵∠1=70°,∴∠BFD=180°-70°=110°.∵∠2=110°,∴∠BFD=∠2,∴AB//DE.(3)∵∠1=70°,∴∠AFD=70°.∵∠2=110°,∴∠AFD+∠2=180°,∴AB//DE.12.证明:∵CE平分∠ACD,,∴∠2=∠DCE.∵∠1=∠2,∴∠DCE=∠1,∴AB ∥CD.第五章 相交线与平行线周周测5一 选择题1.如果相等的两个角的一边在一条直线上,另一边互相平行,那么这两个角( ) A.相等 B.互补 C.相等或互补 D.不能确定2.如图,∠1和∠2互补,那么图中平行的直线是( ) A.b a // B.d c // C.e d // D.e c //第2题图 第4题图3.下列条件中,能得到互相垂直的是( )A.对顶角的平分线B.邻补角的平分线C.平行线的内错角的平分线D.平行线的同位角的平分线 4.如图,n m //,那么∠1.∠2.∠3的关系是( )A.∠1+∠2+∠3=360°B.∠1+∠2-∠3=180°C.∠1-∠2+∠3=180°D.∠1+∠2+∠3=180°5.一辆汽车在直路上行驶,两次拐弯后,仍按原来的方向行驶,那么这两次拐弯时( ) A.第一次向右拐30°,第二次向右拐30°B.第一次向右拐30°,第二次向右拐150°C.第一次向左拐30°,第二次向右拐150°D.第一次向左拐30°,第二次向右拐30° 6.下列命题中,是假命题的是( )A.同旁内角互补B.对顶角相等C.直角的补角仍然是直角D.两点之间,线段最短7.如图,在三角形ABC中,BC=5,∠A=70°,∠B=75°,把三角形ABC沿直线BC的方向平移到三角形DEF的位置.若CF=3,则下列结论中错误的是 ( ) A.DF=5 B.∠F=35°C.BE=3 D.AB∥DE8.如图,将周长为10个单位的三角形ABC沿边BC向右平移2个单位得到三角形DEF,则四边形ABFD周长为()A.12B.14C.16D.18第8题图第9题图第10题图9.如图是一块长方形ABCD的场地,AB=102m,AD=51m,从A.B两处入口中的路宽都为1m,两小路汇合处路宽为2m,其余部分种植草坪,则草坪的面积为()A.5050m2B.4900m2C.5000m2D.4998m210.如图,O是正六边形ABCDEF的中心,下列图形:三角形OCD;三角形ODE;三角形OEF;三角形OAF;三角形OAB.其中可由三角形OBC平移得到的有()A.1个B.2个C.3个D.4个二填空题11.如图,将三角形ABC沿BC方向平移2cm得到三角形DEF,若三角形ABC周长为16cm,则四边形ABFD周长为.第13题图第14题图第15题图12.如图,长方形ABCD的边AB=10,BC=6,则图中四个小长方形的周长和为.13.如图,在长方形ABCD中,AB=10cm,BC=6cm,若此长方形以2cm/s的速度沿着A→B方向移动,则经过 s,平移后的长方形与原来长方形重叠部分的面积为24 . 14.如图,AB∥EF∥CD,EG平分∠BEF,∠B+∠BED+∠D=192°,∠B-∠D=24°,则∠GEF= .15.“两数之和始终是正数”是________命题(填“真”或“假”).16.把命题“平行于同一条直线的两条直线互相平行”改写成“如果……,那么……”的形式为_______________________________________________.17.如图,是我们生活中经常接触的小刀,刀片的外形是一个直角梯形,刀片上.下是平行的,转动刀片时会形成∠1和∠2,则∠1+∠2=度.第17题图第18题图18.如图,AB∥CD,OE平分∠BOC,OF⊥OE,OP⊥CD,∠ABO=40°,则下列结论:①∠BOE=70°;②OF平分∠BOD;③∠POE=∠BOF;④∠POB=2∠DOF.其中正确结论有(只填序号).三解答题19.如图,点A在直线MN上,且MN//BC.求证:∠BAC+∠B+∠C=180°.M A NB C20.如图,M,N,T和P,Q,R分别在同一直线上,且∠1=∠3,∠P=∠T.求证:∠M=∠R.21.如图,直线m⊥l,n⊥l,∠1=∠2.求证:∠3=∠4.22.已知,如图,DE⊥AC,∠AGF=∠ABC,∠1+∠2=180°,试判断BF与AC的位置关系,并说明理由.第五章相交线与平行线周周测5 参考答案与解析一、选择题1.C2.D3.D4.B5.D6.A7.A8.B9.C 10.B二、填空题11.20 12.32 13.3 14.30°15.假16.如果两条直线平行于同一条直线,那么这两条直线互相平行17. 90 18.①②③三、解答题19.证明:∵MN∥BC,∴∠B=∠MAB,∠C=∠NAC.∵∠BAC+∠MAB+∠NAC=180°,∴∠BAC+∠B+∠C=180°.20.证明:∵∠1=∠3,∠1=∠2,∴∠2=∠3,∴PN∥QT,∴∠T=∠MNP.∵∠P=∠T,∴∠P=∠MNP,∴PR∥MT,∴∠M=∠R..21.证明:∵m⊥l,n⊥l,∴m∥n,∴∠1=∠4,∠,2=∠3.∵∠1=∠2,∴∠3=∠4.22.解:BF⊥AC.理由如下:∵∠AGF=∠ABC,∴FG∥BC,∴∠1=∠3.∵∠1+∠2=180°,∠3+∠2=180°,∴BF∥DE,∴∠BFC=∠DEC.∵DE⊥AC,∴∠DEC=90°,∴∠BFC=90°,∴BF⊥AC.第五章相交线与平行线周周测6一选择题1. 下列命题正确的是( )A.两直线与第三条直线相交,同位角相等B.两直线与第三条直线相交,内错角相等C.两直线平行,内错角相等D.两直线平行,同旁内角相等2.如图,小聪把一块含有60°角的直角三角板的两个顶点放在直尺的对边上,并测得∠1=23°,则∠2的度数是()A.23°B.22°C.37°D.67°3.如图,AB∥CD,点E在CB的延长线上.若∠ABE=70°,则∠ECD的度数为()A.20°B.70°C.100°D.110°4.如图,∠B=∠C,AD∥BC,∠BAC=100°,则∠CAD的度数是()A.30°B.35°C.40°D.50°5.如图,已知AB∥CD,EA是∠CEB的平分线,若∠BED=40°,则∠A的度数是()A.40°B.50°C.70°D.80°6.如图,把一块等腰直角三角板的直角顶点放在直尺的一边上,如果∠1=40°,那么∠2=()A.40°B.45°C.50°D.60°7.如图,已知AC∥BD,∠CAE=30°,∠DBE=45°,则∠AEB等于()A.30°B.45°C.60°D.75°8. 如图,已知a∥b,∠1=130°,∠2=90°,则∠3=()A.70°B.100°C.140°D.170°9.如图,AB∥CD,则根据图中标注的角,下列关系中成立的是()A.∠1=∠3 B.∠2+∠3=180°C.∠2+∠4<180°D.∠3+∠5=180°10.如图,已知AB∥CD,CE平分∠ACD,当∠A=120°时,∠ECD的度数是()A.45°B.40°C.35°D.30°11. 如图,点D是三角形ABC的边AB的延长线上一点,BE∥AC.若∠C=50°,∠DBE=60°,则∠CBD的度数等于()A.120°B.110°C.100°D.70°12.如图,AB∥ED,则∠A+∠C+∠D=( )A.180°B.270°C.360°D.540°二填空题13. 如图,已知AB//DE,∠ABC=75°,∠CDE=150°,则∠BCD的度数为.14.如图,已知AD∥BE,∠DAC=29°,∠EBC=45°,则∠ACB= °.15.如图,已知AB∥CD,∠1=130°,则∠2= .16.如图,AB∥CD,∠1=64°,FG平分∠EFD,则∠EGF= °.三解答题17. 如图,BD平分∠ABC,F在AB上,G在AC上,FC与BD相交于点H. ∠GFH+ ∠BHC=180°.求证:.18.如图,已知∠B=∠C,AD∥BC,求证:AD平分∠CAE.19.如图,已知AB//CD,分别写出下列四个图形中,∠P与∠A,∠C的关系,请你从所得的四个关系中任选一个加以证明.20.如图,点E在直线DF上,点B在直线AC上,若∠1=∠2,∠3=∠4,则∠A=∠F,请说明理由.解:∵∠1=∠2(已知),∠2=∠DGF(),∴∠1=∠DGF,∴BD∥CE(),∴∠3+∠C=180º().又∵∠3=∠4(已知),∴∠4+∠C=180º,∴∥DF(同旁内角互补,两直线平行),∴∠A=∠F().第五章相交线与平行线周周测6 参考答案与解析一、选择题1.C2.C3.D4.C5.C6.C7.D8.C9.D 10.D 11.B 12.C二、填空题13.45°14.74 15.50°16.32三、解答题17.证明:∵BD平分∠ABC,∴∠2=∠ABD.∵∠GFH+∠BHC=180°,∠FHD=∠BHC,∴∠GFH+∠FHD=180°,∴FG∥BD,∴∠1=∠ABD.∵∠2=∠ABD,∴∠1=∠2.18.证明:∵AD∥BC,∴∠2=∠B,∠1=∠C.∵∠B=∠C,∴∠1=∠2,∴AD平分∠CAE.19.解:(1)∠P=360°-∠A-∠C.(2)∠P=∠A+∠C.(3)∠P=∠C-∠A.(4)∠P=∠A-∠C.若选(3),证明如下:过点P向左作PQ∥AB,则∠A=∠APQ.∵AB∥CD,∴PQ∥CD,∴∠C=∠CPQ,∴∠CPA=∠CPQ-∠APQ=∠C-∠A.20.对顶角相等同位角相等,两直线平行两直线平行,同旁内角互补AC 两直线平行,内错角相等第五章相交线与平行线周周测7一选择题1.将图①所示的图案通过平移后可以得到的图案是()A B C D 图①2.在5×5方格纸中将图①中的图形N平移后的位置如图②所示,那么下面平移中正确的是()A. 先向下移动1格,再向左移动1格B. 先向下移动1格,再向左移动2格C. 先向下移动2格,再向左移动1格D. 先向下移动2格,再向左移动2格第2题图第3题图3.如图,已知三角形ABC的面积为8,将三角形ABC沿BC的方向平移到三角形A’B’C’的位置,使B’和C重合,连结AC’交A’C于D,则三角形CAC’的面积为()A.4B.6C.8D.164.四根火柴棒形成如图所示的“口”字,平移火柴棒后,原图形能变成的汉字是()5.如图,面积为12cm²的三角形ABC沿BC方向平移至三角形DEF的位置,平移的距离是边BC的2倍,则图中四边形ACFD的面积为()A.24cm²B.36cm²C.48cm²D.60cm²第5题图第6题图6.如图,小明从家到学校有①②③三条路可走,每条路的长分别为a,b,c,则()A. B. C. D.7.从棱长为2的正方体毛坯的一角,挖去一个棱长为1的小正方体,得到一个如图所示的零件,则这个零件的表面积是()A.20 B.22 C.24 D.26第7题图第8题图8.如图,将网格中的三条线段沿网格线平移后组成一个首尾相接的三角形,至少需要移动()A.8格B.9格C.11格D.12格二填空题9.如图,将三角形ABC沿BC方向平移2cm得到三角形DEF,若三角形ABC周长为16cm,则四边形ABFD周长为.第9题图第10题图第11题图10.如图,将三角形ABC沿射线AC平移得到三角形DEF.若AF=17,DC=7,则AD= .11.如图,边长为8cm的正方形ABCD先向上平移4cm,再向右平移2cm,得到正方形A′B′C′D′,此时阴影部分的面积为_________.12.某小区的一块长26米,宽15米的草坪内要修一条如图所示宽度相同的通道.当通道的宽度为2米时,剩下的草坪面积是通道面积的倍.第12题图第13题图第14题图13.鑫都大酒店在装修时,准备在主楼梯(如图)上铺上红地毯,已知这种地毯每平方米售价35元.楼梯宽2米,则购买这种地毯至少需元.14.如图,把直角梯形ABCD沿AD方向平移到梯形EFGH,HG=24cm,WG=8cm,WC=6cm,求阴影部分的面积为cm2.三解答题15.如图,已知,AB∥CD,直线EF分别交AB,CD于点E,F,EG平分∠AEF,∠1=40°,求∠2的度数.16.如图①是长方形纸带,将纸带沿EF折叠成图②,再沿BF折叠成图③.(1)若图①中∠DEF=20°,则图③中∠CFE的度数是多少?(2)若图①中∠DEF=α,把图③中∠CFE的度数用α表示是多少?17.如图,DB∥FG∥EC,∠ABD=60°,∠ACE=36°,AP平分∠BAC.求∠PAG的度数.第五章相交线与平行线周周测7 参考答案与解析一、选择题1.A2.C3.C4.B5.C6.C7.C8.A二、填空题9.20 10.5 11.24cm²12.4 13.630 14.168三、解答题15.解:∵AB∥CD,∠1=40°,∴∠AEG=∠1=40°.∵EG平分∠AEF,,∴∠AEF=2∠AEG=80°,∴∠2=180°-∠AEF=180°-80°=100°.16.解:图①中,∵AD∥BC,∴∠DEF=∠BFE,∴∠CFE=180°-∠DEF.图②中,由折叠得∠CEF=180°-∠DEF,∴∠CFB=∠CEF-∠BFE=180°-2∠DEF.图③中,由折叠得∠CFB=180°-2∠DEF,∴∠CFE=∠CFB-∠BFE=180°-3∠DEF.(1)若图①中∠DEF=20°,则图③中∠CFE=180°-3×20°=120°.(2)若图①中∠DEF=α,则图③中∠CFE=180°-3α.17.解:∵DB∥FG∥EC,∠ABD=60°,∠ACE=36°,∴∠BAG=∠ABD=60°,∠CAG=∠ACE=36°,∴∠BAC=∠BAG+∠CAG=60°+36°=96°.∵AP平分∠BAC,∴∠PAC=12∠BAC=12×96°=48°,∴∠PAG=∠PAC-∠CAG=48°-36°=12°.第五章相交线与平行线周周测8一选择题1.下列选项中能由左图平移得到的是()A. B. C. D.2.在四边形ABCD中,下列各图中∠1与∠2相等的是()3.如图,在铁路旁有一李庄,现要建一火车站,为了使李庄人乘车最方便,请你在铁路线上选一点来建火车站,应建在()A.A点B.B点C.C点D.D点4.将命题“对顶角相等”写成“如果……,那么……”的形式,正确的是()A.如果两个角相等,那么它们是对顶角B.如果两个角是对顶角,那么它们相等C.如果对顶角,那么相等D.如果两个角不是对顶角,那么这两个角不相等5.如图,与∠1是同旁内角的是()A.∠2B.∠3C.∠4D.∠56.如图,AB//CD,∠AGE=128°,HM平分∠EHD,则∠MHD的度数是()A.46°B.23°C.26°D.24°7.如图,下列条件中,不能判断直线l1∥l2的是()A.∠1=∠3B.∠4=∠5C.∠2=∠3D.∠2+∠4=180°8.如图,直线l1∥l2,若∠1=140°,∠2=70°,则∠3的度数是()CA.60°B.65°C.70°D.80°9.如图,已知AD∥BC,∠B=30°,DB平分∠ADE,则∠DEC=()A.30°B.60°C.90°D.120°10.如图,已知AB∥DE,∠ABC=70º,∠CDE=140º,则∠BCD的值为( )A.70ºB.50ºC.40ºD.30º二填空题11.如图,将三角形ABC沿BC’方向平移4cm,得到三角形A’B’C’,那么CC’= cm.12.将一个直角三角板和一把长方形直尺按如图放置,若∠α=54°,则∠β的度数是______.13.如图,把矩形ABCD沿EF对折后使两部分重合,若∠1=40°,则∠AEF=.14.如图,直线a∥b,三角板的直角顶点A落在直线a上,两条直角边分别交直线b于B,C两点.若∠1=42°,则∠2的度数是.15.如图,AB∥CD,∠B=160°,∠D=120°,则∠E=_________16.如图①:MA1∥NA2,图②:MA1∥NA3,图③:MA1∥NA4,图④:MA1∥NA5,…,则第n个图中的∠A1+∠A2+∠A3+…+∠A n+1= °(用含n的代数式表示).三解答题17.完成下面的证明:已知,如图,AB∥CD∥GH,EG平分∠BEF,FG平分∠EFD.求证:∠EGF=90°.证明:∵HG∥AB(已知),∴∠1=∠3(______ ).又∵HG∥CD(已知),∴∠2=∠4.∵AB∥CD(已知),∴∠BEF+______=180°(______ ).又∵EG平分∠BEF(已知),∴∠1=∠______.又∵FG平分∠EFD(已知),∴∠2=∠______,∴∠1+∠2=(______ ),∴∠1+∠2=90°,∴∠3+∠4=90°(______ ),即∠EGF=90°.18.如图是一个汉字“互”字,其中,∥,∠1=∠2,∠=∠.求证:∠=∠.19.如图,CD⊥AB于D,点F是BC上任意一点,FE⊥AB于E,且∠1=∠2,∠3=80°. (1)证明:∠B=∠ADG;(2)求∠BCA的度数.20.如图,EF∥AD,AD∥BC,CE平分∠BCF,∠DAC=120°,∠ACF=20°,求∠FEC的度数.21.如图,已知DC∥FP,∠1=∠2,∠FED=28º,∠AGF=80º,FH平分∠EFG.(1)证明:DC∥AB;(2)求∠PFH的度数.22.如图,已知AB∥CD,C在D的右侧,BM平分∠ABC,DN平分∠ADC,BM,DN所在直线交于点E,∠ADC =70°.(1)求∠EDC的度数;(2)若∠ABC =n°,求∠BED的度数(用含n的代数式表示);(3)将线段BC沿DC方向平移,使得点B在点A的右侧,其他条件不变,画出图形并判断∠BED的度数是否改变,若改变,求出它的度数(用含n的式子表示);若不改变,请说明理由.第五章相交线与平行线周周测8参考答案与解析一、选择题1.C2.B3.A4.B5.A6.C7.C8.C9.B 10.D二、填空题11.4 12.36° 13.110° 14.48° 15.40° 16.180n三、解答题17.两直线平行,内错角相等∠EFD 两直线平行,同旁内角互补 BEF EFD ∠BEF+∠EFD 等量代换18.证明:如图,延长交于点.∵∥,∴∠1=∠3.又∵∠1=∠2,∴∠2=∠3,∴∥HN,∴∠=∠.又∵∠=∠,∴∠=∠.19.(1)证明:∵CD⊥AB,FE⊥AB,∴CD∥EF,∴∠2=∠BCD.∵∠1=∠2,∴∠1=∠BCD,∴BC∥DG,∴∠B=∠ADG.(2)解:∵DG∥BC,∴∠3=∠BCA.∵∠3=80°,∴∠BCA=80°.20.解:∵EF∥AD,AD∥BC,∴EF∥BC,∴∠ACB+∠DAC=180°.∵∠DAC=120°,∴∠ACB=60°.又∵∠ACF=20°,∴∠FCB=∠ACB﹣∠ACF=40°.∵CE平分∠BCF,∴∠BCE=20°.∵EF∥BC,∴∠FEC=∠BCE=20°.21.(1) 证明:∵∠1=∠2,∴AB∥FP.∵DC∥FP,∴DC∥AB.(2)解:∵DC∥FP,∴∠EFP=∠FED=28º.∵AB∥FP,∴∠GFP=∠AGF=80º.∴∠EFG=∠EFP+∠GFP=28°+80°=108°.∵FH平分∠EFG,∴∠EFH=∠EFG=×108°=54°,∴∠PFH=∠EFH-∠EFP=54°-28°=26 º.22.解:(1)∵DE平分∠ADC,∠ADC=70°,∴∠EDC=∠ADC=×70°=35°.(2)如图,过点E向左作EF∥AB.∵AB∥CD,∴AB∥CD∥EF,∴∠ABE=∠BEF,∠CDE=∠DEF.∵BE平分∠ABC,DE平分∠ADC,∠ABC=n°,∠ADC=70°,∴∠ABE=∠ABC=n°,∠CDE=∠ADC=35°,∴∠BED=∠BEF+∠DEF=n°+35°.(3)如图①,过点E向左作EF∥AB.∵BE平分∠ABC,DE平分∠ADC,∠ABC=n°,∠ADC=70°,∴∠ABE=∠ABC=n°,∠CDE=∠ADC=35°.∵AB∥CD,∴AB∥CD∥EF,∴∠BEF=180°-∠ABE=180°-n°,∠CDE=∠DEF=35°,∴∠BED=∠BEF+∠DEF=180°-n°+35°=215°-n°.图①图②如图②,过点E向左作EF∥AB.∵BM平分∠ABC,DE平分∠ADC,∠ABC=n°,∠ADC=70°,∴∠ABM=∠ABC=n°,∠CDE=∠ADC=35°.∵AB∥CD,∴AB∥CD∥EF,∴∠BEF=∠ABM=n°,∠CDE=∠DEF=35°,∴∠BED=∠BEF-∠DEF=n°-35°.综上所述,∠BED的度数发生了改为,改变为215°-n°或n°-35°.第五章相交线与平行线周周测9一选择题1.点P为直线l外一点,点A,B,C为直线l上三点,P A=4cm,PB=5cm,PC=3cm,则点P到直线l的距离为()A.4cm B.5cmC.小于3cm D.不大于3cm2.如图,点E,F分别是AB,CD上的点,点G是BC的延长线上一点,且∠B=∠DCG=∠D,则下列判断中,错误的是()A.∠AEF=∠EFC B.∠A=∠BCFC.∠AEF=∠EBC D.∠BEF+∠EFC=180°第2题图第3题图3.如图,∠AOB的一边OA为平面镜,∠AOB=37°36′,在OB上有一点E,从E点射出一束光线经OA上一点D反射,反射光线DC恰好与OB平行,且∠ODE与∠ADC相等,则∠DEB的度数是()A.75°36′ B.75°12′ C.74°36′ D.74°12′4.下列图形中,可以由其中一个图形通过平移得到的是()5.如图①~④,其中∠1与∠2是同位角的有()A.①②③④B.①②③C.①③D.①第5题图第6题图6.如图,能判断直线AB∥CD的条件是()A.∠1=∠2 B.∠3=∠4C.∠1+∠3=180° D.∠3+∠4=180°7.有下列命题:①对顶角相等;②在同一平面内,垂直于同一条直线的两直线平行;③相等的角是对顶角;④内错角相等.其中假命题有()A.①②B.①③C.②④D.③④8.若∠1与∠2是对顶角且互补,则它们两边所在的直线()A.互相垂直B.互相平行C.既不垂直也不平行D.不能确定9.如图,BD∥AC,BE平分∠ABD,交AC于点E.若∠A=50°,则∠1的度数为() A.65° B.60° C.55° D.50°第9题图第10题图10.已知直线m∥n,将一块直角三角板ABC按如图方式放置(∠ABC=30°),其中A,B两点分别落在直线m,n上.若∠1=20°,则∠2的度数为()A.20° B.30°C.45° D.50°二填空题11.如图,当剪刀口∠AOB增大21°时,∠COD增大________°.第11题图第12题图12.如图,平行线AB,CD被直线AE所截,∠1=50°,则∠A=________°.13.如图,在线段AC,BC,CD中,线段________最短,理由是____________________.第13题图第14题图14.如图,直线AB,CD相交于点O,OE⊥AB,∠COE=68°,则∠BOD的度数为________.15.如图,直线l1∥l2,∠1=20°,则∠2+∠3=________°.第15题图第17题图16.平移变换不仅与几何图形有着密切的联系,而且在一些特殊结构的汉字中,也有平移变换的现象,如:“日”“朋”“森”等,请你再写两个具有平移变换现象的汉字_____ ___.17.如图是超市里购物车的侧面示意图,扶手AB与车底CD平行,∠2比∠3大10°,∠1是∠2的1911倍,则∠2的度数是________.18.以下三种沿AB折叠纸带的方法:(1)如图①,展开后测得∠1=∠2;(2)如图②,展开后测得∠1=∠2且∠3=∠4;(3)如图③,测得∠1=∠2.其中能判定纸带两条边线a,b互相平行的是________(填序号).三解答题19.如图,直线AB,CD相交于O,OE是∠AOD的平分线,∠AOC=28°,求∠AOE的度数.20.如图,在方格纸中,每个小方格的边长均为1个长度单位,三角形ABC的三个顶点和点P都在小方格的顶点上.要求:①将三角形ABC平移,使点P落在平移后的三角形内部;②平移后的三角形的顶点在方格的顶点上.请你在图甲和图乙中分别画出符合要求的一个示意图,并写出平移的方法.21.如图,已知AE⊥BC,FG⊥BC,∠1=∠2.求证:AB∥CD.22.如图,直线AB,CD相交于点O,OE把∠BOD分成两部分.(1)直接写出图中∠AOC的对顶角为________,∠BOE的邻补角为________;(2)若∠AOC=70°,且∠BOE∶∠EOD=2∶3,求∠AOE的度数.23.如图,现有以下3个论断:①AB∥CD;②∠B=∠C;③∠E=∠F.请以其中2个论断为条件,另一个论断为结论构造命题.(1)你构造的是哪几个命题?(2)你构造的命题是真命题还是假命题?请选择其中一个真命题加以证明.24.如图,已知AB∥CD,CE,BE的交点为E,现作如下操作:第一次操作,分别作∠ABE和∠DCE的平分线,交点为E1,第二次操作,分别作∠ABE1和∠DCE1的平分线,交点为E2,第三次操作,分别作∠ABE2和∠DCE2的平分线,交点为E3……第n次操作,分别作∠ABE n-1和∠DCE n-1的平分线,交点为E n.(1)如图①,求证:∠BEC=∠B+∠C;(2)如图②,求证:∠BE2C=14∠BEC;(3)猜想:若∠E n=b°,求∠BEC的度数.第五章相交线与平行线周周测9 参考答案与解析一、选择题1.D2.C3.B4.B5.C6.D7.D8.A9.A 10.D二、填空题11.21 12.50 13.CD 垂线段最短14.22°15.20016.林晶(答案不唯一)17.55°18.①②三、解答题19.解:∵∠AOC=28°,∴∠AOD=180°-∠AOC=180°-28°=152°.∵OE是∠AOD的平分线,∴∠AOE=12∠AOD=12×152°=76°.20.解:如图,共有3种情况:图甲图乙图丙图甲:将三角形ABC向右平移4个单位长度;图乙:将三角形ABC先向右平移4个单位长度,再向上平移1个单位长度;图丙:将三角形ABC先向右平移3个单位长度,再向上平移1个单位长度.21.证明:∵AE⊥BC,FG⊥BC,∴AE∥FG,∴∠1=∠A.∵∠1=∠2,∴∠2=∠A,∴AB∥CD.22.解:(1)∠BOD ∠AOE(2)∵∠AOC=70°,∴∠BOD=70°.∵∠BOE∶∠EOD=2∶3,∴∠BOE=25∠BOD=25×70°=28°,∴∠AOE=180°-∠BOE=180°-28°=152°.23.解:(1)命题一:如果AB∥CD,∠B=∠C,那么∠E=∠F.命题二:如果AB∥CD,∠E=∠F,那么∠B=∠C.命题三:如果∠B=∠C,∠E=∠F,那么AB∥CD.(2)三个命题都是真命题.若选择命题(1),证明如下:∵AB∥CD,∴∠B=∠CDF.∵∠B=∠C,∴∠CDF=∠C,∴AC∥BD,∴∠E=∠F.24.(1)证明:过点E向左作EF∥AB.∵AB∥CD,∴AB∥CD∥EF,∴∠BEC=∠B,∠CEF=∠C,∴∠BEC=∠BEF+∠CEF=∠B+∠C.(2)证明:同(1)理,可证∠BE1C=∠ABE1+∠DCE1,∠BE2C=∠ABE2+∠DCE2.∵∠ABE和∠DCE的平分线交于点E1,∠ABE1和∠DCE1交于点E2,∴∠ABE1=12∠ABE,∠DCE1=12∠DCE,∠ABE2=12∠ABE1,∠DCE2=12∠DCE1,∴∠BE1C=12∠ABE+12∠DCE=12∠BEC,∴∠BE2C=12×12∠ABE+12×12∠DCE=14∠BEC.(3)由(1)(2)知∠BE1C=12∠BEC,∠BE2C=14∠BEC,∴∠∠BE n C=12n⎛⎫⎪⎝⎭∠BEC,∴若∠E n=b°,∠BEC=2n。
周测小卷04(考查范围:第1~4章)

周测小卷04(考查范围:第1 ~ 4章)考试时间60分钟一、选择题1.下列实验能证明蛋白酶具有水解蛋白质作用的最佳方案是()A.在装有蛋清的两试管中分别加入等量的蛋白酶和蒸馏水,然后滴加双缩脲试剂观察是否变成紫色B.在装有煮熟的蛋白块的两试管中分别加入等量的蛋白酶和蒸馏水,一段时间后直接观察蛋白块的大小C.在装有蛋清的两试管中分别加入等量的蛋白酶和蒸馏水,然后滴加斐林试剂加热后观察是否变成砖红色D.在装有煮熟的蛋白块的两试管中分别加入等量的蛋白酶和蒸馏水,然后滴加双缩脲试剂观察是否变成紫色2.下列关于生物体的化学组成的叙述,正确的是()A.无机盐在生物体内主要以化合物的形式存在B.脂质的组成元素与糖类完全相同C.高温会导致蛋白质的肽键断裂D.放线菌和酵母菌的遗传物质是DNA,病毒的遗传物质是DNA或RNA 3.关于DNA和RNA的叙述,正确的是()A.DNA有氢键,RNA没有氢键B.细胞核中的遗传物质是DNA,细胞质中的遗传物质是RNAC.原核细胞中既有DNA,也有RNAD.DNA的主要合成场所是细胞核,RNA的主要合成场所是细胞质4.下列关于组成生命的元素和化合物叙述完全正确的一项是()A.DNA和RNA彻底水解所得产物中都有糖B.人体肌细胞中含量最多的化合物是蛋白质C.组成蛋白质的元素都是大量元素,比如S、Fe等D.噬菌体和烟草花叶病毒的遗传物质都含有硫元素5.神舟八号飞船搭载蛋白质在太空结晶状况良好,结晶体像“钻石”,太空晶体可供研究抗癌新药。
下列关于蛋白质的叙述中正确的是()A.蛋白质结构多样性与构成蛋白质的氨基酸的种类、数目、空间结构有关B.已知某化合物含有C、H、O、N等元素,且具有催化作用,可以推断此物质是蛋白质C.有些蛋白质具有防御功能,如抗体;有些蛋白质具有接受信息的功能,如受体。
抗体和受体都具有特异性D.一条刚刚从核糖体上合成的肽链,其氨基酸的种类、数目及排列顺序便已确定,因此具有生物活性6.科学家用含3H标记的亮氨酸培养豚鼠的胰腺腺泡细胞,下表为在腺泡细胞几种结构中最早检测到放射性的时间表。
好老师教育云南分校专升本2020届--第四次周测

好老师教育云南分校专升本2020届--第四次周测基本信息:[矩阵文本题] *第一题、单项选择题(请选出正确的选项,共20题,每小题1分,共20分)1. If the new safety system to use, the accident would never have happened. ()[单选题] *A. had been put(正确答案)B. were putC. should be putD. would be put2. But for the help of my English teacher, I the first prize in the English Writing Competition. () [单选题] *A. would not winB. would not have won(正确答案)C. would winD. would have won3. Ellen is a fantastic dancer. I wish I as well as her. () [单选题] *A. danceB. will danceC. had dancedD. danced(正确答案)4. I was wearing a safety belt. If I hadn’t been wearing one, I . () [单选题] *A. were injuredB. would be injuredC. had been injuredD. would have been injured(正确答案)5. The workers were not better organized, otherwise they the task in half the time. () [单选题] *A. accomplishedB. had accomplishedC. would accomplishD. would have accomplished(正确答案)6. It is necessary that people both young and old in China some English to be prepared for the Olympic Games to be held in Beijing in 2008. () [单选题] *A. learn(正确答案)B. will learnC. must learnD. have learned7. the morning train, he would not have been late for the meeting. () [单选题] *A. Did he catchB. Should he catchC. Has he caughtD. Had he caught(正确答案)8. If I you, I’d take them away. () [单选题] *A. amB. wasC. Were(正确答案)D. would be9. Without his wartime experiences, Hemingway his famous novel A Farewell to Arms. () [单选题] *A. didn’t writeB. hadn’t writtenC. wouldn’t writeD. wouldn’t have written(正确答案)10. My mom suggests that we out for a change this weekend. () [单选题] *A. should eat(正确答案)B. should be eatenC. should have eatenD. would eat11. If it for his invitation the other day, I should not be here now. () [单选题] *A. had not been(正确答案)B. should not beC. were not to beD. should not have been12. Don’t handle the vase as if it made of steel. () [单选题] *A. isB. were(正确答案)C. has beenD. had been13. —Sorry, Mum! I failed the job interview again. ()—Oh, it’s too bad. You have made full preparations. [单选题] *A. mustB. canC. wouldD. should(正确答案)14. Why didn’t you tell me about your trouble last week? If you me, I could have helped. () [单选题] *A. toldB. had told(正确答案)C. were to tellD. would tell15. Had the governments and scientists not worked together, AIDS-relateddeaths since their highest in 2005. () [单选题] *A. had not fallenB. would not fallC. did not fallD. would not have fallen(正确答案)16. I wish I at my sister’s wedding last Tuesday, but I was on a business trip in New York then. () [单选题] *A. will beB. would beC. have beenD. had been(正确答案)17. It’s high time that we students even harder at our lessons as the examination is coming nearer. () [单选题] *A. workB. will workC. worked(正确答案)D. have to work18. The doctor proposed that you after eating a large meal. () [单选题] *A. shouldn’t have swumB. couldn’t swimC. couldn’t have swumD. shouldn’t swim(正确答案)19. it rain tomorrow, we would stay at home. () [单选题] *A. Should(正确答案)B. BeC. WereD. Will20. If she tomorrow, I would tell her the story. () [单选题] *A. were cameB. would comeC. were to come(正确答案)D. come第二题、多项选择题(请选出题目中拼写错误的单词,其中多选、少选、错选均不得分,共10个小题,每小题1分,合计10分)1. ( ) *A.convinee(正确答案)B.confees(正确答案)C. appeall(正确答案)D. determina(正确答案)2. () *A.imposeB.confrontC. feme(正确答案)D. vltimate(正确答案)3. () *A.regerd(正确答案)B.minde(正确答案)C. motiveD. complain4. () *A.thoroughB.appointe(正确答案)C.confuseD.disappointe(正确答案)5.() *A.faultB.helplessC.estimata(正确答案)D.kompensate(正确答案)6. () *A.epuiq(正确答案)B. essentialpara(正确答案)D. facilitet(正确答案)7. () *A.degreeB.bersist(正确答案)C.conforme(正确答案)D.appropriatee(正确答案)8. () *A.infectionB.establich(正确答案)C.suspectD.enthusiasti(正确答案)9. () *A. flexibla(正确答案)B.arrast(正确答案)C.negotiatee(正确答案)D.resemble10. () *A.integrityB.defensiveC.delieve(正确答案)D.regien(正确答案)第三题、完形填空题(请选出正确的选项,共10道题,每小题1分,共10分)When Rebecca was a middle school student, she was often bullied (欺凌). At that time, she didn’t want to tell others. However, she now thinks people who are bullied should talk about their __1__ .Rebecca says that many people who are bullied __2__ in silence. She says that although she __3__ heard a lot about bullying when she was in primary school, she never thought it would happen to her.Rebecca told us that the bullying began when she went to middle school. People started making fun of her for being a __4__ student and knowing all the answers.She went on to say that every time she answered a question correctly in class, everyone would start shouting and saying that she was too __5__ for them.She told us that by the end of the year, she was very __6__ about the bullying and became ill. She began to hate school. But __7__ she had a friend who could talk to, and they told their head teacher about her problem. She believes that talking to the teacher__8__ her a lot. They found ways to deal with the problem, and the bullying finally__9__.Her __10__ is, don’t see yourself as the problem. Nobody should be bullied. But if you don’t tell anyone what is going on, nobody will know that you need help.1. () [单选题] *A. experiences(正确答案)B. jokesC. hobbiesD. studies2. () [单选题] *A. sleepB. laughC. suffer(正确答案)D. play3. () [单选题] *A. SeldomB. always(正确答案)C. neverD. suddenly4. () [单选题] *A. badB. happyC. silentD. good(正确答案)5. () [单选题] *A. clever(正确答案)B. SlowC. noisyD. proud6. () [单选题] *A. pleasedB. Worried(正确答案)C. satisfiedD. amazed7. () [单选题] *A. usuallyB. interestinglyC. luckily(正确答案)D. strangely8. () [单选题] *A. surprisedB. controlledC. excitedD. helped(正确答案)9. () [单选题] *A. startedB. stopped(正确答案)C. increasedD. continued10. () [单选题] *A. ProblemB. agreementC. conditionD. advice(正确答案)第四题、阅读理解(请选出正确的选项,单选题共5小题,每题2分,共10分) A poor boy lived in a small town. He sold goods from door to door to pay for school. One day, he only had one cent left, and he was hungry. He decided that he would ask for a meal at the next house. However, when a young woman opened the door, the boy was shy, so he just asked for some water. The woman knew he was hungry, so she brought him a large glass of milk. He drank it slowly, and then asked, “How much should I payfor it?”“You won’t pay for it. My mother has told me that it is good to help the people who are in trouble.” She replied. The boy said, “Then I thank you from my heart.” As the boy left that house, he felt stronger. He knew he had many things to do.Many years later, the young woman became ill. The local doctors couldn’t save her. People had to send her to a big city. When the doctor knew who the woman was, he was excited and tried his best to save her life. He succeeded. The woman needed to pay for the medical bill. The doctor learned that she couldn’t afford it. So he wrote something down on the medical bill. The woman read the bill, “You have paid it with a glass of milk.”1. The poor boy sold goods from door to door because . () [单选题] *A. he had no money leftB. he needed money to buy some foodC. he wanted to raise money for Project HopeD. he had to make money for his school(正确答案)2. Why was the young woman sent to a hospital in a big city? () [单选题] *A. Because she was seriously ill.(正确答案)B. Because she had lots of money.C. Because she wanted to visit the doctor.D. Because she knew the poor boy worked there.3. From the passage we can know the doctor (the poor boy) . () [单选题] *A. let the young woman pay for the bill.B. was always thankful for the young woman’s kindness.(正确答案)C. didn’t remember the young woman.D. failed to save the young woman’s life.4. Which is the following sentences is true? () [单选题] *A. The young woman had a bad mother.B. The poor boy asked for some money.C. The young woman and her mother were both kind to others.(正确答案)D. The poor boy became a famous engineer when he grew up.5. What’s the best title for the article? () [单选题] *A. A kind MotherB. A Lovely Young WomanC. A Poor BoyD. A Glass of Milk(正确答案)第五题、阅读理解(请选出正确的选项,单选题共5小题,每题2分,共10分) A group of old classmates, who have succeeded in their work, got together to visit their teacher. Their conversation soon turned to complaining (抱怨) about the stress (压力) in their work and life. The teacher went to the kitchen and returned with a large pot of coffee and many cups. Some of the cups are expensive and lovely, but some are cheap and not beautiful. The teacher told them to help themselves to the coffee.When all the students had a cup of coffee in hand, the teacher said, “Have you noticedall the nice-looking expensive cups were taken, leaving behind the cheap ones? It’s OK for you to want only the best for yourselves, but that is why you have the stress in your work and life even if you’re very successful now.”“All of you really wanted the coffee, not the cups, but you choose the best cups and were eyeing each other’s cups.”“Now think about this: life is the coffee, and money and position in society are the cups. They are just tools to hold life. They do not change the quality (质量) of life. Sometimes, we just care about the cups, and we fail to enjoy the coffee. So, don’t let the cups drive you, enjoy coffee in stead.”1. The students who visited the teacher . () [单选题] *A. are satisfied with their workB. are successful in their studiesC. are strict with each otherD. are successful in their work(正确答案)2. The teacher took out cups . () [单选题] *A. for the students to have coffee(正确答案)B. to show to the studentsC. for the students to have a lookD. to show his favorite coffee3. The teacher noticed that the students . () [单选题] *A. liked the cheap cupsB. only took the best cups(正确答案)C. were drinking coffeeD. preferred the coffee to the cups4. Why did the students have the stress in the work and life? () [单选题] *A. Because they really wanted coffee.B. Because they didn’t have good cups.C. Because they didn’t pay enough attention to life itself.(正确答案)D. Because they didn’t have money to buy coffee and cups.5. From the story, we know the teacher wanted the students to enjoy . () [单选题] *A. the cupsB. the coffeeC. life(正确答案)D. money and position第六题、阅读理解(请选出正确的选项,单选题共5小题,每题2分,共10分)A science fiction flying car looks like a normal car, but it is an aircraft (飞行器) that anybody can fly directly from any place to another without using roads or runways. Science fiction writers have written about flying cars for a long time. But now flying cars will soon fly out of the world of science fiction into our real world. And the dream of the science fiction writers will soon come true.The first-known sky car is the FSC-1. The FSC-1 looks like an expensive sports car. You can drive the FSC-1 on the road like a normal car. If you touch a button, its wings and propeller (螺旋桨) fold out and then it can take off, fly and land as an airplane. The owners of the FSC-1 can choose if they want to drive or fly.Another flying car or sky car is the Moller Skycar M400. Although you can’t drive it on the roads, it is small and easy to fly and can take off and land like a helicopter (直升飞机). Urban Aeronautics’ X-Hawk is another type of sky car. It is expected to be available for about $3 million.Just like any new technology, flying cars have taken a long time to be developed. But some experts think the technology is far from what people imagine when they are sitting in traffic. It still needs to be improved.1. kinds of flying cars are mentioned in the passage. () [单选题] *A. TwoB. Three(正确答案)C. FourD. Five2. The writer thinks that flying cars will be no longer a dream because . () [单选题] *A. science fiction writers’ ideas are stupidB. they are too expensive to makeC. they will soon be available(正确答案)D. they are only in science fiction3. The FSC-1 can . () [单选题] *A. change itself into a robotB. move on water like a shipC. be flown only like an airplaneD. be driven like a car and flown like an airplane(正确答案)4. The Moller Skycar is different from the FSC-1 because . () [单选题] *A. it can’t flyB. it can’t be driven like a car(正确答案)C. it is difficult to landD. it is much more expensive5. Some experts think the technology of flying cars is . () [单选题] *A. normalB. traditionalC. not good enough(正确答案)D. strange第七题、阅读理解(请选出正确的选项,单选题共5小题,每题2分,共10分) Although the United States covers so much land and the land produces far more food than the present population needs, its people are by now almost entirely an urban society.Less than a tenth of the people are engaged in agriculture and forestry(林业), and most of the rest live in or around towns,small and large. Here the traditional picture ischanging: every small town may still be very like other small towns, and the typical small town may represent a widely acceptedview of the country, but most Americans do not live insmall towns anymore. Half the population now lives in some thirty metropolitan areas (large cities with their sub urbs,of more than a million people -- a larger proportion than in Germany or England,let alone France). The statistics(统计) of urban and rural population should be treated with caution because so many people who live in areas classified as rural travel by car to work in a nearby town each day. As the rush to live out of town continues. Rural areas within reach of towns are gradually filled with houses, so that it is hard to say at what moment a piece of country becomes a suburb,but more and more the typical American lives in a metropolitan rather than a small town environment.1. If now America has 250 million people,how many of them are engaged in agriculture and forestry? () [单选题] *A. About 25 million.B. More than 25 million.C. Less than 25 million.(正确答案)D. Less than 225 million.2. Which of the following four countries has the smallest proportion of people living in metropolitan areas? () [单选题] *A. United StatesB. GermanyC. France(正确答案)D. England3. What's the meaning of the word “metropolitan” in the middle of the passage? () [单选题] *A. Of a large city with its suburbs(正确答案)B. Of small and large townsC. Of urban areasD. Of rural areas4. According to the passage, what can we learn about small towns in the United states? () [单选题] *A. Most small towns become gradually crowded.B. Small towns are still similar to each other.(正确答案)C. As the traditional picture is changing, towns are different.D. Small towns are turning into large cities5. Why is it hard to say when a piece of country becomes a suburb? () [单选题] *A. because they are the sameB. Because the rush takes place too quicklyC. Because the process is gradual(正确答案)D. Because more and more Americans live in metropolitan第八题、阅读理解(请选出正确的选项,单选题共5小题,每题2分,共10分) If we were asked exactly what we were doing a year ago, we should probably have to say that we could not remember. But if we had kept a book and had written in it anaccount of what we did each day, we should be able to give an answer to the question.It is the same in history. Many things have been forgotten, because we do not have any written account of them. Sometimes men did keep a record of the most important happenings in their country, but often it was destroyed by fire or in a war. Sometimes there was never any written record at all because the people of that time and place did not know how to write. For example, we know a good deal about the people who lived in China 4, 000 years ago, because they could write and leave written records for those who lived after them. But we know almost nothing about the people who lived even 200 years ago in central Africa. because they had not learned to write.Sometimes,of course, even if the people cannot write, they may know something of the past. They have heard about it from older people, and often songs and dances and stories have been made about the most important happenings, and these have been sung and acted and told for many generations.For most people are proud to tell what their fathers did in the past. This we may call“remembered history”. Some of it has now been written down. It is not so exact or so valuable to us as written history is, because words are much more easily changed when used again and again in speech than when copied in writing. But where there are no written records, such spoken stories are often very helpful.1. Which of the following ideas is not suggested in the passage? () [单选题] *A.“Remembered history”, compared with written history, is less reliableB. Written records of the past play the most important role in our learning of the human historyC. A written account of our daily activities helps us to be able to answer many questionsD. Where there are no written records, there is no history(正确答案)2. We know very little about the central Africa 200 years ago because () [单选题] *A. there was nothing worth being written down at that timeB. the people there ignored the importance of keeping a recordC. the written records were perhaps destroyed by a fireD. the people there did not know how to write(正确答案)3. “Remembered history”refers to () [单选题] *A. history based on a person’s imaginationB. stories of important happenings passed down from mouth to mouthC. songs and dances about the most important eventsD. both B and C(正确答案)4. “Remembered history” is regarded as valuable only when ( ) [单选题] *A. it is written downB. no written account is available(正确答案)C. it proves to be timeD. people are interested in it5. The passage suggests that we could have learned much more about our past than we do now if the ancient people had () [单选题] *A. kept a written record of every past event(正确答案)B. not burnt their written records in warsC. told exact stories of the most important happeningsD. made more songs and dances第九题、阅读理解(请选出正确的选项,单选题共5小题,每题2分,共10分) When families gather for Christmas dinner,some will stick to formal traditions dating back to grandma's generation. Their tables will be set with the good dishes and silver, and the dress code will be Sunday best.But in many other homes,this china-and-silver elegance has given way to a stoneware(粗陶)and stainless informality, with dresses assuming an equally casual-Friday look.For hosts and guests, the change means greater simplicity and comfort.For makers of fine china in Britain, it spells economic hard times.Last week Royal Doulton, the largest employer in Stoke-on-Trent, announced that it is eliminating 1,000 jobs--one-fifth of its total work force.That brings to more than 4, 000 the number of positions lost in 18 months in the pottery(陶瓷)region.Wedgwood and other pottery factories made cuts earlier.Although a strong pound and weak markets in Asia play a role in the downsizing, the layoffs in Stoke have their roots in earthshaking social shifts. A spokesman for royal Doulton admitted that the company “has been somewhat slow in catching up with the trend” toward casual dining. Families eat together less often, he explained, and more people eat alone, either because they are single or they eat in front of television.Even dinner parties, if they happen at all,have gone casual. In a time of long work hours and demanding family schedules, busy hosts insist, rightly, that it's better to share a takeout pizza on paper plates in the family room than to wait for the perfect moment or a “real”dinner party.Too often, the perfect moment never comes. Iron a fine -patterned t ablecloth? For get it.Polish the silver? Who has time?Yet the loss of formality has its down side. The fine points of etiquette(礼节) that children might once have learned at the table by observation or instruction from parents and grandparents.“Chew with your mouth closed”“Keep your elbows off the table” must be picked up elsewhere.Some companies now offer etiquette seminars for employees who may be able professionally but inexperienced socially.1. The trend toward casual dining has has resulted in () [单选题] *A. bankruptcy of fine china manufacturesB. shrinking of the pottery industry(正确答案)C. restructuring of large enterprisesD. economic recession in Great Britain(b)2. Why do people tend to follow the trend to casual dining? () [单选题] *A. Family members need more time to relaxB. Busy schedules leave people no time for formality(正确答案)C. People prefer to live a comfortable lifeD. Young people won't follow the etiquette of the older generation.3. It can be learned from the passage that “Royal Doulton” is () [单选题] *A. a seller of stainless steel tablewareB. a dealer in stonewareC. a pottery chain storeD. a producer of fine china(正确答案)4. The main cause of the layoffs in the pottery industry is ? () [单选题] *A. the increased value of the poundB. the worsening economy in AsiaC. the change in people's way of life(正确答案)D. the fierce competition at home and abroad5. Formal table manners, though less popular than before in current social life () [单选题] *A. are still a must on certain occasions(正确答案)B. are certain to return sooner or laterC. are still being taught by parents at homeD. can help improve personal relationships第十题、翻译判断正误。
浙江初一初中数学月考试卷带答案解析

浙江初一初中数学月考试卷班级:___________ 姓名:___________ 分数:___________一、选择题1.在“百度”搜索引擎中输入“姚明”,能搜索到与之相关的网页约27000000个,将这个数用科学记数法表示为( ) A.2.7×105B.2.7×106C.2.7×107D.2.7×1082.下列各组运算中,运算后结果相同的是()A.43和34B.(﹣5)3和﹣53C.﹣42和(﹣4)2D.和3.在实数﹣,,0.80108,,中,无理数的个数为()A.1个B.2个C.3个D.4个4.如果m表示有理数,那么|m|+m的值()A.可能是负数B.不可能是负数C.必定是正数D.可能是负数也可能是正数5.下列说法:①的平方根是±3;②1的立方根是±1;③>0;④无理数加上无理数一定是无理数;⑤平方根和立方根相同的有理数只有0,其中正确的个数为()A.1个B.2个C.3个D.4个6.下列说法正确的是()A.的系数是﹣2B.32ab3的次数是6次C.是多项式D.x2+x﹣1的常数项为17.小飞测量身高近似1.71米,若小飞的身高记为x,则他的实际身高范围为()A.1.7≤x≤1.8B.1.705<x<1.715C.1.705≤x<1.715D.1.705≤x≤1.7158.某市的出租车的起步价为10元(行驶不超过3千米),以后每增加1千米,加价1.8元,现在某人乘出租车行驶P千米的路程(P>3)所需费用是()A.10+1.8P B.1.8P C.10-1.8P D.10+1.8(P-3)9.若实数a、b、c在数轴上对应点的位置如图所示, 则|c|-|b-a|+|b+c|等于 ( )A.-a B.-a+2b C.-a-2c D.a-2b10.电子跳蚤游戏盘(如图)为△ABC,AB=8,AC=9,BC=10,如果电子跳蚤开始时在BC边的P0点,BP=4,第一步跳蚤从P0跳到AC边上P1点,且CP1=CP;第二步跳蚤从P1跳到AB边上P2点,且AP1=AP2;第三步跳蚤从P2跳回到BC边上P3点,且BP3=BP2;……跳蚤按上述规则跳下去,第次落点为Pn,则P4与P2014之间的距离为()A.0B.1C.4D.5二、填空题1.若x的立方根是,则x=______.2.由四舍五入得到的近似数精确到___________位.3.设a、b互为相反数,c、d互为倒数,则=______________4.若代数式4x﹣5与的值相等,则x的值是__________5.若x=5时,代数式的值是10;x=-5时代数式的值是____________。
2024-2025学年北师大版初一上学期期末数学试题与参考答案
2024-2025学年北师大版数学初一上学期期末复习试题(答案在后面)一、选择题(本大题有10小题,每小题3分,共30分)1、下列数中,最大的负数是()A、-3B、-2C、-1D、02、一个长方形的长是8厘米,宽是5厘米,那么这个长方形的面积是()平方厘米。
A、40B、15C、32D、393、下列哪个数是负数?A、-3B、3C、0D、-54、在数轴上,点A表示的数是-2,点B表示的数是5,那么点A和点B之间的距离是多少?A、3B、7C、5D、-35、已知一个长方形的长是6cm,宽是3cm,求这个长方形的面积。
A. 15cm²B. 18cm²C. 24cm²D. 36cm²6、在直角坐标系中,点A的坐标为(2,-3),点B的坐标为(-4,5),求线段AB 的长度。
A. 5B. 7C. 10D. 137、(1)若(x2−5x+6=0),则(x)的值是:A. 2 或 3B. 1 或 6C. 2 或 -3D. 1 或 -68、(2)若(a2=b2),且(a≠b),则(a)和(b)的关系是:A.(a=b)B.(a=−b)C.(a)和(b)互为相反数D.(a)和(b)互为倒数9、(1)下列数中,是负数的是:A. -5B. 3C. 0D. -3.5 10、(2)一个长方形的长是5厘米,宽是3厘米,那么这个长方形的周长是:A. 14厘米B. 15厘米C. 16厘米D. 18厘米二、填空题(本大题有5小题,每小题3分,共15分)1、一个长方形的长是6厘米,宽是宽的3/4。
这个长方形的面积是________ 平方厘米。
2、如果a、b、c是等差数列的前三项,且a+b+c=18,a-b+c=12,那么b的值为________ 。
3、在等腰三角形ABC中,底边BC的长度为8cm,腰AB的长度为10cm,则底边上的高AD的长度为 ____cm。
4、已知一元二次方程x^2 - 4x + 3 = 0,则该方程的解为 ______ 。
成都七中育才学校初2022届初一上数学第4周周练试卷
七中育才学校初2022届(上期)数学第四周周练班级: 姓名: 学号: 命题:秦玲 审题:廖广 一、选择题(每小题3分)1.如图,将直角三角形ABC 绕斜边AB 所在直线旋转一周得到的几何体是( )A .B .C .D .2.下列两个数互为相反数的是( ) A .81-与8.0+ B .31与333.0- C .6-和)6(-- D .14.3-和π3.在A 、B 、C 内分别填上适当的数.使得它们折成正方体后,对面上的数互为倒数,则填入正方形A 、B 、C 的三数依次是:( ) A .21 ,31 ,1 B .31,21,1 C .1,21,31 D .21,1,314.绝对值等于本身的数一定是( )A 、正数B 、负数C 、0D 、非负数5. 已知5,a a b =-=,则b 等于( )A.+5B.-5C.0D.+5或-5 6.下列说法正确的是( )A .一个数的绝对值等于它本身,这个数一定是正数B .一个数的绝对值等于它的相反数,这个数一定是负数C .绝对值越大,这个数越大D .两个负数,绝对值大的那个数反而小7.数轴上到2的距离等于5的点表示的数是( ).A.3B.7C.3-D.3-或7 8.式子|2x ﹣1|+2取最小值时,x 等于( ) A .2B .﹣2C .D .﹣9.有理数a ,b 在数轴上的位置如图所示,则下列结论不正确的是( )A .a ﹣(﹣b )<0B .a ﹣b <0C .﹣a ﹣b >0D .﹣a +b <010.如果a +b +c =0,且|a |>|b |>|c |,则下列式子可能成立的是( ) A .c >0,a <0B .a >0,b >0C .b >0,c <0D .b =0二、填空题(每小题4分)11.如图,是一个由若干个长、宽、高相等的小正方体摆 成的几何体的主视图、左视图和俯视图,则组成这个几何 体共用了 __________ 个小正方体.12.(1)比较大小:﹣|﹣1| ﹣1.66(2)﹣ ﹣(填“>”“<”或“=”) 13.在下列各数中:﹣3,﹣2.5,+2.25,0,+0.1,+3,π,﹣4,﹣x ,10,非负整数的个数是 .14.如果a -3与a+1互为相反数,那么a= .15.若0>a ,0<b 且0<+b a ,那么有理数a ,b ,,a -b 大小关系是 三、解答题16.计算(每小题4分)(1)﹣20﹣(﹣18)+(﹣14)+13 (2)18+(﹣12)+(﹣21)﹣(﹣12)(3)0.35+(﹣0.6)+0.25﹣(+5.4) (4)(+1.125)﹣(+3)﹣(+)+(﹣0.25)17.(4分)规定图形表示运算a ﹣b +c ,图形表示运算x +z ﹣y ﹣w .则+ = (要求写出计算过程)题号 1 2 3 4 5 6 7 8 9 10 答案18.(10分)某次数学单元检测,708班A1小组六位同学计划平均成绩达到80分,组长在登记成绩时,以80分为基准,超过80分的分数记为正,成绩记录如下:+10,﹣2,+15,+8,﹣13,﹣7.(1)本次检测成绩最好的为多少分?(2)该小组实际总成绩与计划相比是超过还是不足,超过或不足多少分?(3)本次检测小组成员中得分最高与最低相差多少分?19.(10分)由8个边长为1的相同小立方块搭成的几何体如图所示:(1)请画出它的三视图.(2)请计算它的表面积.俯视图20.(10分)(1)明明同学计算(﹣4)﹣1﹣(﹣18)+(﹣13)时,他是这样做的:Array(1)明明的解法从第几步开始出现错误,改正后并计算出正确的结果:(2)仿照明明的解法,请你计算:(﹣102)﹣(﹣96)+54+(﹣48)B 卷(50分)21. (4分)已知8,5a b ==,且a b a b +=+,则a b -= 22.(4分)如图,是由一些小立方块所搭几何体的三种视图,若在所搭几何体的基础上(不改变原几何体中小立方块的位置),继续添加相同的小立方块,以搭成一个大正方体,至少还需要 个小立方块.23.(4分)若,|||2|c b a --=+-则.____________=++c b a24.(4分)如果0<<y x ,则xyxy xx +的结果是25.(4分))x 、y 、z 在数轴上的位置如图所示,则化简|x ﹣y|+|z ﹣y|的结果是___________26.(8分)计算:11×3+12×4+13×5+⋯+118×2027.(10分) 已知:a 、b 互为相反数,c 、d 乘积为1,12x +=,求:2()x x a b cd-++的值;28.(12分)已知a 是最大的负整数,b 是﹣5的相反数,c =﹣|﹣2|,且a 、b 、c 分别是点A 、B 、C 在数轴上对应的数.(1)求a 、b 、c 的值,并在数轴上标出点A 、B 、C .(2)若动点P 从点A 出发沿数轴正方向运动,动点Q 同时从点B 出发也沿数轴正方向运动,点P 的速度是每秒3个单位长度,点Q 的速度是每秒1个单位长度,求运动几秒后,点P 可以追上点Q ?(3)在数轴上找一点M ,使点M 到A 、B 、C 三点的距离之和等于12,请求出所有点M 对应的数.。
初一数学期中考试试卷分析反思5篇
初一数学期中考试试卷分析反思5篇初一数学期中考试试卷分析反思1一、试卷分析试卷满分120分,共有23道题。
试卷总体难度系数较高,但学问点的考查挨次支协作理,层次清楚。
试卷整体质量比较高,体现了中学数学课程标准对同学把握学问和应用力气的要求,有利于推动前进学校数学课堂教学改革和新课程的实施。
考查的学问点有坐标系中点的坐标特征、平行线的判定及性质、二元一次方程组、确定值加减、平移求面积等。
二、成果分析我教的是七五班和七三班,各班的平均分、及格率以及优秀率,如下表:其中,五班高于63分的共有19个人,其中4个人经过加强学习与训练可以考及格。
及格的人共有15人,高于80分的同学共有7个人,3个人是高于85分,而这些人依据平常的表现都能考到优秀,特殊具有潜力。
三班高于60分的共有16个人,有4个同学成果徘徊在及格线四周。
及格的也共有12个人,高于80分的同学有7个人,高于85分的有4个人,而这些同学都有潜力考到优秀。
三、答题分析选择题中同学出错率较高的是第2题和第6题,缘由都是做题时不细心,往开头做时是一个答案,检查时又将答案改错,还是基础概念把握的不结实。
选择题第8题往往是审题及观看力气不够导致正确率很低。
填空题中错误率较高的是第12题,14题,15题,这三道题同学平常做过但一般都是以大题的形式消逝,所以当这些题被当成填空题消逝时,同学就会掉以轻心不认真审题。
因此,导致消逝了过多错误。
计算题都是一些关于有理数的加减乘除混合运算以及整式的加减之类的常见题型。
同学照旧存在一些问题,而这些问题都是由于不细心、不认真造成的。
大题同学消逝错误较多的是20、21、23这三道题,错误缘由都是由于同学审题不清,在读题、审题环节上的马虎造成的。
还有是由于综合素养差,很多同学没有验证。
四、对策措施1.争论新课标的教学理念:留意力气培育、留意探究精神、留意实践力气、留意过程、留意科学素养、留意创新力气、留意动手力气等等,在教学中如何去体现,是今后教学中关注的重点。
初一年级第四 次周测成绩表
1917 1841 1929 1931 1813 1901 935 1922 417 817 504 2018 310 1930 745 235 538 925 236 713 418 147 607 914 1345 203 647 704 714 635 1203 520 1204 1017 1003 701 1245 1320 741 1131 139 942 525 1432
201610101 201610102 201610103 201610104 201610105 201610106 201610107 201610108 201610109 201610110 201610111 201610112 201610113 201610114 201610115 201610116 201610117 201610118 201610119 201610120 201610121 201610122 201610123 201610124 201610125 201610126 201610127 201610128 201610129 201610130 201610131 201610132 201610133 201610134 201610135 201610136 201610137 201610138 201610139 201610140 201610141 201610142 201610143 201610144
徐龙 沈磊 陶乐 李彧 王玉 程阳 高宇昕 王志强 卫俊 谷翰林 茹严海 丁书堃 卞思芹 李元聪 巫思宇 朱申奥 朱禧龙 汤畅 邱天磊 刘泽 杨雯婷 邢齐鹏 郑木焱 张慧 韩一鸣 尚琴 金贤鹏 朱志远 赵胜男 陈建平 黄之瑜 徐济祥 张龙 陈秋涵 刘伟 孔伟嘉 杨梦琪 陈延飞 姚昌坤 唐佳俊 王瑾 章天瑞 刘梓涵 杨梦莹 谢宇翔 尹贤慧 徐喆
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9. My namee
10. —Welcome to our school.
—.
A. Yes, I amB. Oh, goodC. Thank youD. No, I’m not
11. Li lei plays football very _______ .He is a _______ football player.
C. Listening to music.D. Reading.
45. How old is Mary?
A. 11.B. 12.C. 13.D. 14.
49. How long does Mary play foo tball every day?
A. For half an hour.B. For an hour.
A at B of C. in D .to
15.--_______ do you watch TV every week ?
---Three times
A. How many times B How long C. When D. What time
二、完形填空
I’m Millie. I’m 1236old. I have black37and black hair. I38born in Beijing and I live39Hoping Road. I have a brother.40name is Andy. I like41TV and Andy42listening to the radio. I have43of good friends at school. Mary is my classmate. She is my44friend. She is a good student. She wants to be a doctor when she45up.
A. He often reads some books.B. He often has a rest
C. He often watches TV.D. He often plays basketball.
53. Whic h is NOT true(正确的)?
A. John likes reading.B. John likes playing basketball.
My name is Mary. I am thirteen years old. I was born in America but I live in Tianjin now. I am in Grade 8. I am short and strong. I like sports very much. I like football. I play it for half an hour after school every day. I want to be a football player.
C.Ronaldo says he likes football .And he wants to play in the 2014 World Cup
56.C.Ronaldo was born in __________
A. Spain B. Manchester C. Madrid D. Portugal
42.A. likeB. loveC. enjoysD. enjoy
43.A. lotB. lotsC. a lotsD. lot a
44.A. goodB. betterC. bestD. well
45.A. getsB. putsC . ringsD. grows
三、阅读理解(每小题2分,满分30分)
13 .She _____ meals and ____English at home on Sundays.
A cooks; studies B. cook ; studies C. cooks ;study D. cook .study
14.We often play computer games _______ the weekend
57. What club did C.Ronaldo play for in 2008?
A .Real Madrid B, Manchester United C. A club in Portugal D. We don’t know
58. When is the next World Cup?
51. What time does John have breakfast at the weekend?
A. At about 8:30 am.B. At about 9:30 am.
C. At about 10:30 am.D. At about 11:30 am.
52. What does John often do in the afternoon at the weekend?
C. For tw o hours.D. For three hours.
50. Where is Mary from?
A. China.B. America.
C. England.D. Japan.
B
I am John. I always get up late at the weekend. At about 9:30 am, I have breakfast.After breakfast, I start doing my homework. We have lunch at about 12:00, and then I watch TV or have a rest(休息). I like reading and I often read some interesting books in the afternoon. I like sports, too. Sometimes I play football or basketball with my friends at school. My school is near my home, so I can walk there. Every weekend, my father takes me to a restaurant for a big dinner. I can enjoy lots of nice food. I like my weekend.
C,Ronaldo is young .He has many hobbies .He likes listening to music and seeing films .His favourite colours are white and red .His favourite number is 7
A good ;well B ,well ;good C, well ;well D ,good ;good
12.---_______?
---He looks tall and strong
A How is he B .How does he look C. What does he like D .How is he like
A
My name is Zhang Hua. I am from Nanjing, China. I am twelve. I am in Grade 7. I have short hair and big eyes. I am tall and slim. I play too many computer games, so I wear glasses. I like listening to music very much.
36.A. monthB. monthsC. yearD. years
37.A. mouthB. nos eC. eyesD. eye
38.A. amB. isC. wasD. are
38.A. inB. on C. forD. with
40.A. HisB. HeC. HerD. She
41.A. watchB. watchesC. to watchD. watching
46. What grade is Zhang Hua in?
A. In Grade 6.B. In Grade 7.
C. In Grade 8.D. In Grade 9.
47. What does Zhang Hua like doing?
A. Playing football.B. Playing volleyball.
A. areB. isC. amD. be
6. He loves _________.
A. readsB. readingC. readD. readding
7.sheher homework?
A. Do; doesB. Does; doC. Do; doD. Does; does
8. Is your brother good ________ Chinese?
A. In 2014 B. In 2012 C. In 2013 D. In 2016
59.What does C.Ronaldo like ?
55. Who take(s) John for a big dinner at the weekend?
A. H is brother.B. His father.
C. His grandparents.D. His friends.
C
All football fans(迷)know C. Ronaldo. Many people like him and some say he is the best football player in the world .He looks tall and strong .He was born in 1985 in Portugal(葡萄牙).He now plays for a Spanish(西班牙)club ------Real Madrid(皇马).he came to the Real Madrid from Manchester United(曼联)in 2009 ,He is good at scoring(射门得分)and he scored 54 goals in the 2010---2011 season(赛季)