You really play tennis well. I believe you will become a star in the future.
A:great trainer
B:famous player
C:good learner
已知O为坐标原点,向量OA→=(1,3),OB→=(3,-1),且AP→=2PB→,则点P的坐标为( )
材料二和材料三反映了我国古代哪一历史典故?后来禹用什么方法使得治水成功?