A:Nobody is perfect
B:Congratulations!
C:Bad luck!
D:You really did badly
—What's the of the stadium?
—It looks like an egg.
△ABC的顶点B在平面α内,A、C在α同侧,A′、C′是A、C的在平面α内的射影,且A′、C′、B三点共线,则平面ABC与平面α( )