已知:如图,OC⊥AB,DE平分∠AOC,那么∠AOE等于 ( )
A:135°
B:50°
C:45°
D:155°
Hong Kong is _______ the south of China.
如图,在梯形ABCD中,AD∥BC,AC与BD相交于点O,AC=BC,点E在DC的延长线上,∠BEC=∠ACB,已知BC=9,cos∠ABC= 13 .