A:①④⑤②⑥③
B:①④⑤②③⑥
C:⑤②③①⑥④
D:⑤②①③④⑥
She thinks that the opera____ understand.
②∠AOC+∠BOD=90°;③若OC平分∠AOB,则OB平分∠COD;④∠AOD的平分线与∠COB的平分线是同一条射线. 其中正确的个数有( )