2020年浙江省温州市南浦实验中学中考专题(三)开放型问题%28无答案%29
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2020年浙江省温州市中考数学模拟试卷(三)一、选择题(本大题共10小题,共40.0分)1.下列图案中,既是中心对称图形又是轴对称图形的是()A. B. C. D.2.关于x的一元二次方程x2+ax−1=0的根的情况是()A. 有两个相等的实数根B. 有两个不相等的实数根C. 只有一个实数根D. 没有实数根3.下列运算中,正确的是()A. x6÷x2=x3B. (−3x)2=6x2C. 3x3−2x2=xD. (x3)2⋅x=x74.从一堆苹果中任取了20个,称得它们的质量(单位:克),其数据分布表如下.则这堆苹果中,质量不小于120克的苹果数约占苹果总数的()分组(90,100)(100,110)(110,120)(120,130)(130,140)(140,150)频数1231031A. 80%B. 70%C. 40%D. 35%5.如图,已知∠ACB=∠DBC,添加以下条件,不能判定△ABC≌△DCB的是()A. ∠ABC=∠DCBB. ∠ABD=∠DCAC. AC=DBD. AB=DC6.当x=3时,函数y=x−2的值是()A. −2B. −1C. 0D. 17.如果反比例函数y=kx的图象经过点(−2,3),那么k的值是()A. −32B. −6 C. −23D. 68.将图1围成图2的正方体,则图1中的红心“”标志所在的正方形是正方体中的()A. 面CDHEB. 面BCEFC. 面ABFGD. 面ADHG9.如图,在长70m,宽40m的矩形花园中,欲修宽度相等的观赏路(阴影部分),要使观赏路面积占总面积的17,则路宽x m应满足的方程是()A. (40−x)(70−x)=400B. (40−2x)(70−3x)=400C. (40−x)(70−x)=2400D. (40−2x)(70−3x)=240010.如图,从点A看一山坡上的电线杆PQ,观测点P的仰角是45°,向前走6m到达B点,测得顶端点P和杆底端点Q的仰角分别是60°和30°,则该电线杆PQ的高度()A. 6+2√3B. 6+√3C. 10−√3D. 8+√3二、填空题(本大题共6小题,共30.0分)11.在平面直角坐标系中,点A(2,−3)关于y轴对称的点的坐标为______.12.抛物线y=x2向左平移3个单位,再向下平移2个单位后,所得的抛物线表达式是______.13.如图是甲、乙两射击运动员10次射击成绩的折线统计图,则这10次射击成绩更稳定的运动员是______.14.如图,第1个图形有1个三角形,第2个图形中有5个三角形,第3个图形中有9个三角形,……,则第2019个图形中有______个三角形.(x>0)图象上的两点,过点A,B分别作AC⊥x 15.如图,点A,B是反比例函数y=kx轴于点C,BD⊥x轴于点D,连接OA,BC.已知点C(2,0),BD=2,S△BCD=3,则S△AOC=____.16.如图,AC是圆内接四边形ABCD的一条对角线,点D关于AC的对称点E在边BC上连接AE.若∠ABC=64°,则∠BAE的度数为____.三、解答题(本大题共8小题,共80.0分)17.(1)计算:|−2|+√4−(−1)2(2)解方程:4x−3=2(x−1).18.如图,在△ABC中,AB=AC,CD是∠ACB的平分线,DE//BC,交AC于点E.(1)求证:DE=CE.(2)若∠CDE=35°,求∠A的度数.19.已知△ABC中,点A(−1,2),B(−3,−2),C(3,−3).(1)在直角坐标系中,画出△ABC;(2)求△ABC的面积.20.为了解某市九年级学生学业考试体育成绩,现从中随机抽取部分学生的体育成绩进行分段(A:50分;B:49−45分;C:44−40分;D:39−30分;E:29−0分)统计如下:学业考试体育成绩(分数段)统计表分数段人数(人)频率A480.2B a0.25C840.35D36bE120.05根据上面提供的信息,回答下列问题:(1)在统计表中,a的值为______,b的值为______,并将统计图补充完整(温馨提示:作图时别忘了用0.5毫米及以上的黑色签字笔涂黑);(2)甲同学说:“我的体育成绩是此次抽样调查所得数据的中位数.”请问:甲同学的体育成绩应在什么分数段内?______(填相应分数段的字母)(3)如果把成绩在40分以上(含40分)定为优秀,那么该市今年10440名九年级学生中体育成绩为优秀的学生人数约有多少名?21.如图,在平面直角坐标系xOy中,一次函数y1=ax+b(a,b为常数,且a≠0)与反(m为常数,且m≠0)的图象交于点A(−2,1)、B(1,n).比例函数y2=mx(1)求反比例函数和一次函数的解析式;(2)连结OA、OB,求△AOB的面积;(3)直接写出当y1<y2<0时,自变量x的取值范围.22.如图,在Rt△ABC中,∠C=90°,AD平分∠BAC,交BC于点D,点O在AB上,⊙O经过A,D两点,交AB于点E,交AC于点F(1)求证:BC是⊙O的切线;(2)若⊙O半径是2cm,F是弧AD的中点,求阴影部分的面积(结果保留π和根号)23.某商场要经营一种新上市的文具,进价为20元/件.试营销阶段发现:当销售单价是25元时,每天的销售量为250件;销售单价每上涨1元,每天的销售量就减少10件.(1)写出商场销售这种文具,每天所得的销售利润w(元)与销售单价x(元)之间的函数关系式;(2)求销售单价为多少元时,该文具每天的销售利润最大;(3)商场的营销部结合上述情况,提出了A、B两种营销方案:方案A:该文具的销售单价高于进价且不超过30元;方案B:每天销售量不少于10件,且每件文具的利润至少为25元请比较哪种方案的最大利润更高,并说明理由.24.如图,矩形ABCD中,AB=6,BC=6√3,动点P从点A出发,以每秒√3个单位长度的速度沿线段AD运动,动点Q从点D出发,以每秒2个单位长度的速度沿折线段D−O−C运动,已知P、Q同时开始移动,当动点P到达D点时,P、Q同时停止运动.设运动时间为t秒.(1)当t=1秒时,求动点P、Q之间的距离;(2)若动点P、Q之间的距离为4个单位长度,求t的值;(3)若线段PQ的中点为M,在整个运动过程中;直接写出点M运动路径的长度为______.答案和解析1.【答案】C【解析】解:A 、不是轴对称图形,是中心对称图形,故此选项不合题意;B 、是轴对称图形,不是中心对称图形,故此选项不合题意;C 、是轴对称图形,也是中心对称图形,故此选项符合题意;D 、不是轴对称图形,也不是中心对称图形,故此选项不合题意.故选:C .根据轴对称图形与中心对称图形的概念求解.此题主要考查了中心对称图形与轴对称图形的概念,轴对称图形的关键是寻找对称轴,图形两部分折叠后可重合;中心对称图形是要寻找对称中心,旋转180度后两部分重合. 2.【答案】B【解析】解:△=a 2−4×1×(−1)=a 2+4.∵a 2≥0,∴a 2+4>0,即△>0,∴方程x 2+ax −1=0有两个不相等的实数根.根据方程的系数结合根的判别式,即可得出△=a 2+4>0,由此即可得出方程x 2+ax −1=0有两个不相等的实数根.本题考查了根的判别式,牢记“当△>0时,方程有两个不相等的实数根”是解题的关键.3.【答案】D【解析】解:A 、错误,应为x 6÷x 2=x 6−2=x 4;B 、错误,应为(−3x)2=9x 2;C 、错误,3x 3与2x 2不是同类项,不能合并;D 、(x 3)2⋅x =x 6⋅x =x 7,正确.故选D .根据同底数幂的除法,积的乘方及合并同类项法则计算.本题考查涉及到同底数幂的乘法、除法,幂的乘方、积的乘方等幂的相关运算,学生易于混淆这几个幂的运算的法则,把同底数幂的除法,指数相除,错误的选择A.积的乘方,却把每个因式与指数相乘了,而错误的选择了B .4.【答案】B【解析】解:10+3+11+2+3+10+3+1=1420=70%,所以在整体中质量不小于120克的苹果数约占苹果总数的70%.故选:B .在样品中,质量不小于120克的苹果20个中有14个,通过计算在样本中所占比例来估计总体.本题考查的是通过样本去估计总体,只需将样本“成比例地放大”为总体即可. 5.【答案】D【解析】解:A 、∵在△ABC 和△DCB 中{∠ABC =∠DCB BC =CB ∠ACB =∠DBC∴△ABC≌△DCB(ASA),故本选项不符合题意;B 、∵∠ABD =∠DCA ,∠DBC =∠ACB ,∴∠ABD +∠DBC =∠ACD +∠ACB ,即∠ABC =∠DCB ,∵在△ABC 和△DCB 中{∠ABC =∠DCB BC =CB ∠ACB =∠DBC∴△ABC≌△DCB(ASA),故本选项不符合题意;C 、∵在△ABC 和△DCB 中{BC =CB ∠ACB =∠DBC AC =DB∴△ABC≌△DCB(SAS),故本选项不符合题意;D 、根据∠ACB =∠DBC ,BC =BC ,AB =DC 不能推出△ABC≌△DCB ,故本选项符合题意;故选:D .根据全等三角形的判定定理逐个判断即可.本题考查了全等三角形的判定定理,能灵活运用全等三角形的判定定理进行推理是解此题的关键,注意:全等三角形的判定定理有SAS ,ASA ,AAS ,SSS .6.【答案】D【解析】解:当x =3时,函数y =x −2=3−2=1,故选:D .把x 的值代入函数关系式计算,得到答案.本题考查的是函数值的求法,函数值是指自变量在取值范围内取某个值时,函数与之对应唯一确定的值.7.【答案】B【解析】解:把(−2,3)代入函数解析式,得3=k−2,∴k =−6.故选:B .把(−2,3)代入函数解析式即可求k .本题考查了反比例函数图象上点的坐标特征,经过函数的某点一定在函数的图象上. 8.【答案】A【解析】解:由图1中的红心“”标志,可知它与等边三角形相邻,折叠成正方体是正方体中的面CDHE .故选A .由平面图形的折叠及正方体的展开图解题.注意找准红心“”标志所在的相邻面. 本题考查了正方体的展开图形,解题关键是从相邻面入手进行分析及解答问题. 9.【答案】D【解析】解:由图可得,(40−2x)(70−3x)=40×70×(1−17),即(40−2x)(70−3x)=2400,故选:D.根据题意和图形中的数据可以列出相应的一元二次方程,从而可以解答本题.本题考查由实际问题抽象出一元二次方程,解答本题的关键是明确题意,列出相应的一元二次方程.10.【答案】A【解析】解:延长PQ交直线AB于点E,设PE=x米.在直角△APE中,∠A=45°,则AE=PE=x米;∵∠PBE=60°∴∠BPE=30°在直角△BPE中,BE=√33PE=√33x米,∵AB=AE−BE=6米,则x−√33x=6,解得:x=9+3√3.则BE=(3√3+3)米.在直角△BEQ中,QE=√33BE=√33(3√3+3)=(3+√3)米.∴PQ=PE−QE=9+3√3−(3+√3)=6+2√3(米).答:电线杆PQ的高度是6+2√3米.故选:A.延长PQ交直线AB于点E,设PE=x米,在直角△APE和直角△BPE中,根据三角函数利用x表示出AE和BE,根据AB=AE−BE即可列出方程求得x的值,再在直角△BQE 中利用三角函数求得QE的长,则PQ的长度即可求解.本题考查了仰角的定义,以及三角函数,正确求得PE的长度是关键.11.【答案】(−2,−3)【解析】【分析】此题主要考查了关于y轴对称的点的坐标,关键是掌握点的坐标的变化规律.根据关于y轴对称点的坐标特点:横坐标互为相反数,纵坐标不变可得答案.【解答】解:点A(2,−3)关于y轴对称的点的坐标为(−2,−3),故答案为:(−2,−3).12.【答案】y=(x+3)2−2【解析】解:由“左加右减”的原则可知,将抛物线y=x2向左平移3个单位所得的抛物线的表达式是y=(x+3)2;由“上加下减”的原则可知,将抛物线y=(x+3)2向下平移2个单位所得的抛物线的表达式是y=(x+3)2−2.故答案为:y=(x+3)2−2.直接根据“上加下减,左加右减”的原则进行解答即可.本题考查了二次函数的图象与几何变换,熟知函数图象平移的法则是解答此题的关键.13.【答案】甲【解析】解:由图可知甲的成绩为9,7,8,9,8,9,7,9,9,9,乙的成绩为8,9,7,8,10,7,9,10,7,10,甲的平均数是:(9+7+8+9+8+9+7+9+9+9)÷10=8.4,乙的平均数是:(8+9+7+8+10+7+9+10+7+10)÷10=8.5,甲的方差S甲2=[2×(7−8.4)2+2×(8−8.4)2+6×(9−8.4)2]÷10=0.64,乙的方差S乙2=[3×(7−8.5)2+2×(8−8.5)2+2×(9−8.5)2+3×(10−8.5)2]÷10=1.45,则S甲2<S乙2,所以这10次射击成绩更稳定的运动员是甲.故答案为:甲.根据所给的折线图求出甲、乙的平均成绩,再利用方差的公式进行计算,即可求出答案.本题考查的是方差:一组数据中各数据与它们的平均数的差的平方的平均数,叫做这组数据的方差.方差是反映一组数据的波动大小的一个量.方差越大,则平均值的离散程度越大,稳定性也越小;反之,则它与其平均值的离散程度越小,稳定性越好.也考查了折线统计图.14.【答案】8073【解析】解:由图可得,第1个图形有1个三角形,第2个图形中有1+4=5个三角形,第3个图形中有1+4+4=1+4×2=9个三角形,……,则第2019个图形中有:1+4×(2019−1)=8073个三角形,故答案为:8073.根据题目中的图形,可以发现三角形个数的变化规律,从而可以解答本题.本题考查图形的变化类,解答本题的关键是明确题意,发现题目中的三角形个数的变化规律.15.【答案】5【解析】【分析】由三角形BCD为直角三角形,根据已知面积与BD的长求出CD的长,由OC+CD求出OD的长,确定出B的坐标,代入反比例解析式求出k的值,利用反比例函数k的几何意义求出三角形AOC面积即可.此题考查了反比例函数系数k的几何意义,以及反比例函数图象上点的坐标特征,熟练掌握反比例函数k的几何意义是解本题的关键.【解答】解:∵BD⊥CD,BD=2,BD⋅CD=3,即CD=3,∴S△BCD=12∵C(2,0),即OC=2,∴OD=OC+CD=2+3=5,∴B(5,2),,代入反比例解析式得:k=10,即y=10x则S△AOC=5,故答案为:516.【答案】52°【解析】解:∵圆内接四边形ABCD,∴∠D=180°−∠ABC=116°,∵点D关于AC的对称点E在边BC上,∴∠D=∠AEC=116°,∴∠BAE=∠AEC−∠ABC=116°−64°=52°.故答案为:52°.直接利用圆内接四边形的性质,结合三角形外角的性质得出答案.此题主要考查了圆内接四边形的性质以及三角形的外角,正确得出∠AEC的度数是解题关键.17.【答案】解:(1)原式=2+2−1=4−1=3;(2)去括号得:4x−3=2x−2,移项合并得:2x=1,解得:x=0.5.【解析】(1)原式利用绝对值的代数意义,算术平方根定义,以及乘方的意义计算即可求出值;(2)方程去括号,移项合并,把x系数化为1,即可求出解.此题考查了实数的运算,以及解一元一次方程,熟练掌握运算法则及方程的解法是解本题的关键.18.【答案】(1)证明:∵CD是∠ACB的平分线,∴∠BCD=∠ECD.∵DE//BC,∴∠EDC=∠BCD,∴∠EDC=∠ECD,∴DE=CE.(2)解:∵∠ECD=∠EDC=35°,∴∠ACB=2∠ECD=70°.∵AB=AC,∴∠ABC=∠ACB=70°,∴∠A=180°−70°−70°=40°.【解析】(1)根据角平分线的性质可得出∠BCD=∠ECD,由DE//BC可得出∠EDC=∠BCD,进而可得出∠EDC=∠ECD,再利用等角对等边即可证出DE=CE;(2)由(1)可得出∠ECD=∠EDC=35°,进而可得出∠ACB=2∠ECD=70°,再根据等腰三角形的性质结合三角形内角和定理即可求出∠A的度数.本题考查了等腰三角形的判定与性质、平行线的性质以及角平分线,解题的关键是:(1)根据平行线的性质结合角平分线的性质找出∠EDC=∠ECD;(2)利用角平分线的性质结合等腰三角形的性质求出∠ACB=∠ABC=70°.19.【答案】解:(1)△ABC如图所示;(2)△ABC的面积=6×5−12×2×4−1 2×1×6−12×5×4,=30−4−3−10,=30−17,=13.【解析】(1)根据平面直角坐标系找出点A、B、C的位置,然后顺次连接即可;(2)根据三角形所在的矩形的面积减去四周三个小直角三角形的面积列式计算即可得解.本题考查了坐标与图形性质,三角形的面积,熟练掌握网格结构以及点的坐标位置的确定方法是解题的关键.20.【答案】解:(1)600.15如图所示:(2)C(3)0.8×10440=8352(名)答:该市九年级考生中体育成绩为优秀的学生人数约有8352名.【解析】解:(1)随机抽取部分学生的总人数为:48÷0.2=240,∴a=240×0.25=60,b=36÷240=0.15,(2)∵总人数为240人,∴根据频率分布直方图知道中位数在C分数段;(3)见答案【分析】(1)首先根据:频数÷总数=频率,由表格A中的数据可以求出随机抽取部分学生的总人数,然后根据B中频率即可求解a,同时也可以求出b;(2)根据中位数的定义可以确定中位数的分数段,然后确定位置;(3)首先根据频率分布直方图可以求出样本中在25分以上(含25分)的人数,然后利用样本估计总体的思想即可解决问题.本题考查了频数分布直方图,训练了学生读频数分布直方图的能力和利用统计图获取信息的能力;利用统计图获取信息时,必须认真观察、分析、研究统计图,才能作出正确的判断和解决问题.21.【答案】解:(1)∵A(−2,1),∴将A 坐标代入反比例函数解析式y 2=m x 中,得m =−2, ∴反比例函数解析式为y =−2x ;将B 坐标代入y =−2x ,得n =−2,∴B 坐标(1,−2),将A 与B 坐标代入一次函数解析式中,得{−2a +b =1a +b =−2, 解得a =−1,b =−1,∴一次函数解析式为y 1=−x −1;(2)设直线AB 与y 轴交于点C ,令x =0,得y =−1,∴点C 坐标(0,−1),∴S △AOB =S △AOC +S △COB =12×1×2+12×1×1=32;(3)由图象可得,当y 1<y 2<0时,自变量x 的取值范围x >1.【解析】(1)将A 坐标代入反比例函数解析式中求出m 的值,即可确定出反比例函数解析式;将B 坐标代入反比例解析式中求出n 的值,确定出B 坐标,将A 与B 坐标代入一次函数解析式中求出a 与b 的值,即可确定出一次函数解析式;(2)设直线AB 与y 轴交于点C ,求得点C 坐标,S △AOB =S △AOC +S △COB ,计算即可;(3)由图象直接可得自变量x 的取值范围.本题属于反比例函数与一次函数的交点问题,涉及的知识有:待定系数法求函数解析式,三角形面积的求法,坐标与图形性质,利用了数形结合的思想,熟练掌握待定系数法是解本题的关键.22.【答案】解:(1)连接OD ,∵OA =OD ,∴∠OAD =∠ODA ,∵∠OAD =∠DAC ,∴∠ODA =∠DAC ,∴OD//AC ,∴∠ODB =∠C =90°,∴OD ⊥BC ,∴BC 是⊙O 的切线;(2)∵AD 平分∠BAC ,∴DE⏜=DF ⏜, ∵F 是弧AD 的中点,∴DF⏜=AF ⏜, ∴DE⏜=DF ⏜=AF ⏜, ∴∠EOD =60°,∵OD =2,∴BD =2√3,∴阴影部分的面积=S △BDO −S 扇形EOD =12×2√3×2−60⋅π×22360=2√3−23πcm 2.【解析】(1)连接OD ,只要证明OD//AC 即可解决问题;(2)根据圆周角定理得到DE⏜=DF ⏜,求出∠EOD =60°,根据扇形的面积公式即可得到结论.本题考查了切线的判定和性质,扇形的面积的计算,角平分线定义,圆周角定理,正确的作出辅助线是解题的关键.23.【答案】解:(1)由题意得,销售量=250−10(x −25)=−10x +500, 则w =(x −20)(−10x +500)=−10x 2+700x −10000;(2)w =−10x 2+700x −10000=−10(x −35)2+2250.∵−10<0,∴函数图象开口向下,w 有最大值,当x =35时,w 最大=2250,故当单价为35元时,该文具每天的利润最大;(3)A 方案利润高.理由如下:A 方案中:20<x ≤30,故当x =30时,w 有最大值,此时w A =2000;B 方案中:{−10x +500≥10x −20≥25, 故x 的取值范围为:45≤x ≤49,∵函数w =−10(x −35)2+2250,对称轴为直线x =35,∴当x =45时,w 有最大值,此时w B =1250,∵w A >w B ,∴A 方案利润更高.【解析】(1)根据利润=(销售单价−进价)×销售量,列出函数关系式即可;(2)根据(1)式列出的函数关系式,运用配方法求最大值;(3)分别求出方案A 、B 中x 的取值范围,然后分别求出A 、B 方案的最大利润,然后进行比较.本题考查了二次函数的应用,难度较大,最大销售利润的问题常利用函数的增减性来解答,我们首先要吃透题意,确定变量,建立函数模型,然后结合实际选择最优方案.其中要注意应该在自变量的取值范围内求最大值(或最小值),也就是说二次函数的最值不一定在x =−b2a 时取得. 24.【答案】解:(1)如图1中,作QK ⊥AD 于K .∵四边形ABCD 是矩形,∴BC =AD =6√3,∠BAD =90°,∴tan∠BDA=ABAD =√33,∴∠BDA=30°,当t=1时,DQ=2,QK=12DQ=1,DK=√3,∵PA=√3,∴PK=4√3,∴PQ=√QK2+PK2=√12+(4√3)2=7.(2)①如图1中,当0<t≤3时,QK=t,PK=6√3−2√3t,∵PQ=4,∴t2+(6√3−2√3t)2=42,解得t=2或4613(舍弃);②如图2中,当3<t≤6时,作QH⊥AD于H,由题意:AQ=2t,AH=√3t,∵AP=√3t,∴AH=AP,∴P与H重合,当PQ=4时,AQ=8,∴2t=8,∴t=4,综上所述,t=2或4秒时,PQ=4.(3)3+3√132.【解析】解:(1)见答案;(2)见答案;(3)如图3中,作OK⊥AD于K,QH⊥AD于H.∵四边形ABCD是矩形,∴OD=OA,∵OK⊥AD,∴DK=AK,∵DH=PA=√3t,∴KH =PK ,当Q 在D 点时,P 在A 点,此时M 在K 点,当Q 在O 点时,P 在K 点,此时M 在E 点,∵在运动过程中,MK//HQ ,MQ =MP ,∴点M 在线段OK 上,当点Q 从D 到O 时,点M 的运动距离为KE =12OK =32.如图4中,当点Q 在线段OC 上时,取CD 的中点M′,OK 的中点M ,连接MM′,则点M 的运动轨迹是线段MM′.在Rt △OMM′中,MM′=√OM′2+OM 2=√(3√3)2+(32)2=3√132, ∴在整个运动过程中,点M 运动路径的长度为3+3√132. 故答案为3+3√132. (1)如图1中,作QK ⊥AD 于K ,求出QK 、PK ,利用勾股定理即可解决问题;(2)分两种情形:①如图1中,当0<t ≤3时;②如图2中,当3<t ≤6时,分别求解即可解决问题;(3)分两种情形:①如图3中,作OK ⊥AD 于K ,QH ⊥AD 于H.当点Q 从D 到O 时,点M 的运动距离=12OK ;②如图4中,当点Q 在线段OC 上时,取CD 的中点M′,OK 的中点M ,连接MM′,则点M 的运动轨迹是线段MM′.由此即可解决问题;本题考查四边形综合题,矩形的性质,勾股定理,锐角三角函数,三角形中位线定理等知识,解题的关键是灵活运用所学知识解决问题,学会用分类讨论的方法思考问题,属于中考压轴题.。
2023年浙江省温州市南浦实验中学等校中考三模英语试题学校:___________姓名:___________班级:___________考号:___________一、完形填空2.A.dealt with B.searched for C.went over D.pointed out 3.A.click B.sing C.take D.leave 4.A.five B.six C.seven D.eight 5.A.strict B.bored C.tired D.serious 6.A.size B.price C.sound D.colour 7.A.stand B.teach C.afford D.choose 8.A.together with B.instead of C.according to D.in front of 9.A.job B.party C.present D.suggestion 10.A.sad B.moved C.anxious D.relaxed 11.A.musicians B.scientists C.artists D.doctors 12.A.Luckily B.Honestly C.Actually D.Probably 13.A.so B.or C.and D.because 14.A.kept B.drew C.bought D.borrowed 15.A.talent B.effort C.surprise D.support二、阅读单选16.________ are necessary to make Earl Grey.① A teaspoon②Hot water③Tea leaves④ Milk⑤A teapotA.①②④B.②③⑤C.②③④D.③④⑤17.When enjoying Earl Grey, we ________.A.must drink it in the afternoon B.should drink it with the a leavesC.have to add sugar and lemon in it D.can enjoy sweets at the same time 18.The passage can be found on a (n) ________.A.newspaper B.magazine C.poster D.websiteThe United Nations has 6 official languages. Each of them has their own days with the aim to show the rich history and culture of each language. UNESCO first created Chinese Language Day in 2010 to celebrate Chinese as one of the six official languages of the United Nations.The first Chinese Language Day was in 2010 on November 12th. But since 2011, it has been on the 20th of April. The date was chosen from Guyu (“Rain of Millet*”) to remember Cangjie. Cangjie is very important in ancient China who was believed to invent Chinese characters 5000 years ago. Legend* says that Cangjie had 4 eyes and he was good at observing*. He often watched the sun and the moon with his upper 2 eyes while watched mountains and rivers with the lower 2 eyes. His long-time observation inspired him to create the earliest written characters according to the shapes of things. When his work was over, it rained millet upon the earth.This year’s Chinese Language Day was held in New York, under the theme of “Chinese Wisdom for a Green World” to provide Chinese wisdom and solutions for green and long-lasting development. World-famous writer Mr. Liu Cixin gave an online lecture to share his opinions on sustainable development and the protection of mother earth.Chinese Language Day is an important carrier for Chinese learners, lovers, and users from all over the world to get close to Chinese. Nowadays, more than one sixth of world’s population speak Chinese as their first language— that’s more than any other population in the world! Learning Chinese is more like a key to knowing China and feeling the beauty of Chinese culture.19.The Chinese Language Day was first created ________.A.in 2011B.13 years agoC.to celebrate Guyu D.to remember Cangjie 20.According to the legend, how did Cangjie observe to create the characters?A.B.C.D.21.From the passage, which of the following is TRUE?A.The theme of this year is about how to be green in China.B.Liu Cixin showed up in New York for the celebration this year.C.The Chinese Language Day is important for people over the world.D.More than 16 percent of world’s population are Chinese native speakers.22.Why does the writer write the passage?A.To tell a legend about Cangjie B.To show the history Chinese.C.To attract foreigners to come to China.D.To introduce some facts of a special day.Recently, a group of Chinese scientists took things a step further by using 3D printing technology to create realistic models of human organs. In the past, it was challenging to create a single material that could print all human organs because they are very different from each other. The Chinese research team started by using hydrogel, a soft gel-like material, as the main material.Scientists use hydrogel and other materials for printing human organs. They have various hardness, such as our bones being the hardest and our brains being the softest. To copy the hardness of human organs, the researchers added metallic elements to the hydrogel and regulate their ratio. In this way, some models can be hard, like the bone, and some can besoft. However, the structure inside the human body is also unbelievably complicated, even in the same organ, different parts require different levels of hardness. To make sure the printing results are correct, the team used a specific technology called light-curing in the 3D printing process. A special light was placed under the printing machine, causing the gel to become strong right after it was printed.________. They usually cannot be used for organ transplanting directly, because human cells are likely to recognize them as “enemies” and start to fight against them. These days, scientists are working on bio-printing: using 3D printing technology to build up various types of cells and materials layer by layer. After that, the printed product will be more acceptable to grow inside the human body. However, this method is in development, and experts are still on the way. They hope it will be used in the medical field within a few years, according to CNN.These 3D printed organ models are used in various fields, such as testing medical tools and presenting operations. Compared to live organs and animal models, they are also ethically acceptable since they are man-made and printed. To some degree, they can help researchers develop new treatments more efficiently, due to their lower relative cost, commented the Alliance of Advanced Biomedical Engineering website.23.In the past, what was the main challenge when printing human organs?A.The cost of printing organs was too high to afford.B.It was hard to use one material for different organs.C.There were too many organs for researchers to print.D.The printing technology was still in the development.24.The research team make the printing results right by ________.A.adding more gel in the process of printingB.controlling the number of metallic elementsC.using light-curing technology while printingD.putting a special light over the printing machine25.Which sentence can be put in the “________” in Paragraph 3?A.However, the hydrogel materials are not perfectB.The hydrogel materials are quite expensive to developC.Besides, the hydrogel materials have more advantagesD.The hydrogel materials have been applies in many ways26.From the passage, we know that hydrogel is ________.A.used as a main material B.a hard material like metalC.accepted by human bodies D.invented by Chinese experts三、多任务混合阅读One Spring dusk, Peter happened to save a swan in the forest of Savernake. Unexpectedly, the swan turned out to be the magic king of the forest. To pay back Peter’s kind action, the king decided to give him a reward. Peter thought twice and asked for two wishes. The king warned him to use the wishes well and left him two leaves to make wishes.He thought back on his life, finding it was satisfying but a little lonely. So he held one leaf and said, “I wish I had a wife.” Then, he put the other one carefully in the notecase. Suddenly, there was a big noise in the river and a beautiful woman appeared. Leita, the woman, told him she was his wife. Then he took her to his house. Leita made herself a good wife and they lived a happy life.But as time went by, Peter began to feel Leita was not happy. One day he found Leita down by the river, weeping.“Leita, what happened?” he asked gently.“You know I love you but I miss the forest, cool grass and the feel of the water sliding over my feathers.”Now he understood what Leita really was. “Is it so hard to be a human being?” asked Peter sadly.“Very, very hard.” she answered, starting to cry again.In the following days, Peter tried everything to make Leita happy but only to find how thinner and paler she was growing, Then he realised hopelessly she would never be happy as a human.That night he made up his mind. When Leita was sleeping, he kissed her goodbye, then took the leaf from his notecase and made a wish. Next moment, lying there was a sleeping swan. He carefully carried it out to the river and gently put her into the river. She woke up and rested her head lightly against his hand. Next instant, she flew away. Looking at its backLearn from moral models五、短文汉语提示填空A group of oldMore than 6,000 years ago, the incense craft and its culture appeared. It became参考答案:1.D 2.B 3.A 4.B 5.D 6.C 7.C 8.B 9.C10.B 11.A 12.A 13.D 14.B 15.D【导语】本文是一篇记叙文。
2021-2022中考数学模拟试卷注意事项:1. 答题前,考生先将自己的姓名、准考证号填写清楚,将条形码准确粘贴在考生信息条形码粘贴区。
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一、选择题(本大题共12个小题,每小题4分,共48分.在每小题给出的四个选项中,只有一项是符合题目要求的.)1.函数228y x x m =--+的图象上有两点()11,A x y ,()22,B x y ,若122x x <<-,则( )A .12y y <B .12y y >C .12 y y =D .1y 、2y 的大小不确定2.已知一个多边形的内角和是外角和的3倍,则这个多边形是( ) A .五边形B .六边形C .七边形D .八边形3.小明和小张两人练习电脑打字,小明每分钟比小张少打6个字,小明打120个字所用的时间和小张打180个字所用的时间相等.设小明打字速度为x 个/分钟,则列方程正确的是( ) A .1201806x x=+ B .1201806x x =- C .1201806x x =+ D .1201806x x=- 4.已知反比例函数y=﹣6x,当1<x <3时,y 的取值范围是( ) A .0<y <1B .1<y <2C .﹣2<y <﹣1D .﹣6<y <﹣25.若数a ,b 在数轴上的位置如图示,则( )A .a +b >0B .ab >0C .a ﹣b >0D .﹣a ﹣b >06.若关于x 的不等式组324x a x a <+⎧⎨>-⎩无解,则a 的取值范围是( )A .a≤﹣3B .a <﹣3C .a >3D .a≥37.互联网“微商”经营已成为大众创业新途径,某微信平台上一件商品标价为200元,按标价的五折销售,仍可获利20元,则这件商品的进价为( ) A .120元B .100元C .80元D .60元8.如图,在△ABC 中,∠AED=∠B ,DE=6,AB=10,AE=8,则BC 的长度为( )A .152B .154C .3D .839.将直线y=﹣x+a 的图象向右平移2个单位后经过点A (3,3),则a 的值为( ) A .4 B .﹣4 C .2 D .﹣210.如图,将△ABC 绕点C 顺时针旋转90°得到△EDC .若点A ,D ,E 在同一条直线上,∠ACB=20°,则∠ADC 的度数是( )A .55°B .60°C .65°D .70°11.某小组7名同学在一周内参加家务劳动的时间如下表所示,关于“劳动时间”的这组数据,以下说法正确的是( ) 劳动时间(小时) 3 3.5 4 4.5 人 数1132A .中位数是4,众数是4B .中位数是3.5,众数是4C .平均数是3.5,众数是4D .平均数是4,众数是3.512.下列运算正确的是( ) A .a 3•a 2=a 6B .(a 2)3=a 5C .9 =3D .2+5=25二、填空题:(本大题共6个小题,每小题4分,共24分.)13.如图,在Rt △ABC 中,∠ACB =90°,∠A =30°,BC =2,点D 是边AB 上的动点,将△ACD 沿CD 所在的直线折叠至△CDA 的位置,CA'交AB 于点E .若△A'ED 为直角三角形,则AD 的长为_____.14.已知x +y =8,xy =2,则x 2y +xy 2=_____.15.关于x 的方程kx 2﹣(2k+1)x+k+2=0有实数根,则k 的取值范围是_____. 16.如图,直线y =k 1x +b 与双曲线2k y=x交于A 、B 两点,其横坐标分别为1和5,则不等式k 1x <2kx +b 的解集是▲.17.如图△ABC中,∠C=90°,AC=8cm,AB的垂直平分线MN交AC于D,连接BD,若cos∠BDC=35,则BC的长为_____.18.如图,某商店营业大厅自动扶梯AB的倾斜角为31°,AB的长为12米,则大厅两层之间的高度为____米.(结果保留两个有效数字)(参考数据;sin31°=0.515,cos31°=0.857,tan31°=0.601)三、解答题:(本大题共9个小题,共78分,解答应写出文字说明、证明过程或演算步骤.19.(6分)如图,在65⨯的矩形方格纸中,每个小正方形的边长均为1,线段AB的两个端点均在小正方形的顶点上.在图中画出以线段AB为底边的等腰CAB∆,其面积为5,点C在小正方形的顶点上;在图中面出以线段AB为一边的ABDE,其面积为16,点D和点E均在小正方形的顶点上;连接CE,并直接写出线段CE的长.20.(6分)如图,抛物线y=ax2+bx(a<0)过点E(10,0),矩形ABCD的边AB在线段OE上(点A在点B的左边),点C,D在抛物线上.设A(t,0),当t=2时,AD=1.求抛物线的函数表达式.当t为何值时,矩形ABCD的周长有最大值?最大值是多少?保持t=2时的矩形ABCD不动,向右平移抛物线.当平移后的抛物线与矩形的边有两个交点G,H,且直线GH平分矩形的面积时,求抛物线平移的距离.21.(6分)如图,在平面直角坐标系xOy 中,一次函数y =x 与反比例函数()0ky k x=≠的图象相交于点()3,A a .(1)求a 、k 的值;(2)直线x =b (0b >)分别与一次函数y =x 、反比例函数ky x=的图象相交于点M 、N ,当MN =2时,画出示意图并直接写出b 的值.22.(8分)解方程(2x+1)2=3(2x+1) 23.(8分)如图,在直角三角形ABC 中,(1)过点A 作AB 的垂线与∠B 的平分线相交于点D (要求:尺规作图,保留作图痕迹,不写作法); (2)若∠A=30°,AB=2,则△ABD 的面积为 .24.(10分)现有两个纸箱,每个纸箱内各装有4个材质、大小都相同的乒乓球,其中一个纸箱内4个小球上分别写有1、2、3、4这4个数,另一个纸箱内4个小球上分别写有5、6、7、8这4个数,甲、乙两人商定了一个游戏,规则是:从这两个纸箱中各随机摸出一个小球,然后把两个小球上的数字相乘,若得到的积是2的倍数,则甲得1分,若得到积是3的倍数,则乙得2分.完成一次游戏后,将球分别放回各自的纸箱,摇匀后进行下一次游戏,最后得分高者胜出.。