已知等差数列{ an }的公差为d(d≠0),且a3+ a 6+ a 10+ a 13=32,若am=8,则m为( )
A:12
B:8
C:6
D:4
Yao Ming is one of the most popular basketball ____ (play) around the world.
设α,β分别为两个不同的平面,直线l⊂α,则“l⊥β”是“α⊥β”成立的( )