A:40
B:30
C:60
D:50
太守谓谁,庐陵欧阳修也
He often____ ____on Saturday.
如图,椭圆E:x2a2+y2b2=1(a>b>0)的离心率是22,点P(0,1)在短轴CD上, 且PC→·PD→=-1.
—Yes, they .