— . He might already have it.
A:No problem
B:I don't agree
C:You can't do that
D:You'd better not
如图,在Rt△ABC中,∠C=90°,∠A=40°,则∠B=____
促使阿尔卑斯山脉隆起成山的两个相互碰撞的板块是( )
1周角=____个直角.