第Ⅰ卷
选择题:本大题共12小题,每小题5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.
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【答案】D
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【答案】B
【解析】
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【答案】C
【解析】
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【答案】B
【解析】
试题分析:由题意,这是几何概型问题,班车每30分钟发出一辆,小明到达时间总长度为40,等车不超过10分钟,符合题意的是是7:50-8:00,和8:20-8:30,故所求概率为
,选B.
(5)已知方程–=1表示双曲线,且该双曲线两焦点间的距离为4,则n的取值范围是
(A)(–1,3) (B)(–1,) (C)(0,3) (D)(0,)
【答案】A
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(6)如图,某几何体的三视图是三个半径相等的圆及每个圆中两条相互垂直的半径.若该几何体的体积是,则它的表面积是
(A)17π (B)18π (C)20π (D)28π
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【答案】A
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(7)函数y=2x2–e|x|在[–2,2]的图像大致为
(A)
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(C)
(D)
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【答案】C
【解析】
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