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2018年安徽省初中毕业学业考试数学押题卷B(卷Ⅰ)
本卷共计3大题,时间45分钟,满分92分
一、选择题(本大题共10小题,每小题4分,满分40分)
1.(-2)2的算术平方根是···········································( )
A.2 B.±2 C.-2 D.
2.计算(-3x)2·x3的结果是···········································( )
A.5x5 B.x6 C.-x5 D.-x6
3.不等式组的解在数轴上表示为·································( )
A. B. C. D.
4.如图,直线AB,CD交于点O,OT⊥AB于O,CE∥AB交CD于点C,若∠ECO=30°,则∠DOT等于·······( )
A.30° B.45° C.60° D.120°
5.为了了解某小区居民的用水情况,随机抽查了该小区10户家庭的月用水量,结果如下表所示.则这10户家庭月用水量的众数和中位数分别为···············································( )
月用水量/t
10
13
14
17
18
户数
2
2
3
2
1
A.14 t,13.5 t B.14 t,13 t C.14 t,14 t D.14 t,10.5 t
第8题图
第4题图
第10题图
第9题图
6.某商品原价200元,连续两次降价a%后售价为148元,下列所列方程正确的是·················( )
A.200(1+a%)2=148 B.200(1-a%)2=148C.200(1-2a%)=148 D.200(1-a2%)=148
7.圆锥体的底面半径为2,侧面积为8π,则其侧面展开图的圆心角为·······················( )
A.90° B.120° C.150° D.180°
8.如图,小明随意向水平放置的大正方形内部区域抛一个小球,则小球停在小正方形内部(阴影)区域的概率为······( )
A. B. C. D.
9.如图,所示的二次函数y=ax2+bx+c的图象中,刘星同学观察得出了下面四条信息:(1)b2-4ac>0;(2)c>1;(3)2a-b