—Because I met my primary school classmate ________________ on the street.
A:by accident
B:by mistake
C:in danger
尺规作图作∠AOB的平分线方法如下:以O为圆心,任意长为半径画弧交OA、OB于C、D,再分别以点C、D为圆心,以大于12CD长为半径画弧,两弧交于点P,作射线OP由作法得△OCP≅△ODP的根据是( )