17.若集合A={x|-2<x<1},B={x|x<-1或x>3},则A∩B=( )
| A. | {x|-2<x<-1} | B. | {x|-2<x<3} | C. | {x|-1<x<1} | D. | {x|1<x<3} |
12.已知椭圆C:$\frac{{x}^{2}}{{a}^{2}}+\frac{{y}^{2}}{{b}^{2}}$=1(a>b>0)的左、右顶点分别为A1,A2,且以线段A1A2为直径的圆与直线bx-ay+2ab=0相切,则C的离心率为( )
| A. | $\frac{\sqrt{6}}{3}$ | B. | $\frac{\sqrt{3}}{3}$ | C. | $\frac{\sqrt{2}}{3}$ | D. | $\frac{1}{3}$ |
11.在正方体ABCD-A1B1C1D1中,E为棱CD的中点,则( )
| A. | A1E⊥DC1 | B. | A1E⊥BD | C. | A1E⊥BC1 | D. | A1E⊥AC |
10.设x,y满足约束条件$\left\{\begin{array}{l}{3x+2y-6≤0}\\{x≥0}\\{y≥0}\end{array}\right.$则z=x-y的取值范围是( )
| A. | [-3,0] | B. | [-3,2] | C. | [0,2] | D. | [0,3] |
9.复平面内表示复数z=i(-2+i)的点位于( )
| A. | 第一象限 | B. | 第二象限 | C. | 第三象限 | D. | 第四象限 |
8.已知集合A={1,2,3,4},B={2,4,6,8},则A∩B中元素的个数为( )
0 239600 239608 239614 239618 239624 239626 239630 239636 239638 239644 239650 239654 239656 239660 239666 239668 239674 239678 239680 239684 239686 239690 239692 239694 239695 239696 239698 239699 239700 239702 239704 239708 239710 239714 239716 239720 239726 239728 239734 239738 239740 239744 239750 239756 239758 239764 239768 239770 239776 239780 239786 239794 266669
| A. | 1 | B. | 2 | C. | 3 | D. | 4 |