A:必有三点共线
B:必有三点不共线
C:至少有三点共线
D:不可能有三点共线
——This is between you and me. ——I promise. I won't tell others ______you say I can.
已知直线l与椭圆C: x2a2 + y2b2 =1(a>b>0)交于A、B两点,M为线段AB的中点,延长OM交椭圆C于P.