She was a____ (显然) a very nervous woman, and that affected her career.
The terrible car accident ____ (使...受伤)the driver and five children.
高度集中的计划经济体制的特点是 ( )
①国家运用指令性计划,直接掌握、控制人财物资源 ②权力主要集中在中央
③经济管理权限过分集中 ④国家包购包销,企业无权销售
若椭圆C1:x2a12+y2b12=1(a1>b1>0)和椭圆C2:x2a22+y2b22=1(a2>b2>0)的焦点相同且a1>a2.给出如下四个结论:①椭圆C1和椭圆C2一定没有公共点; ②a1a2>b1b2;③a12-a22=b12-b22; ④a1-a2<b1-b2.其中,所有正确结论的序号是( )
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