共面对象

cognate objects───同根宾语；同源宾语

cognate object───同根宾语；同源宾语

found objects───找到的对象

BL Lac objects───BL Lac对象

clear objective───明确目标

coplanarity───n.[数]共面性；共面；同面性

countersubjects───对题

Position relationship problem between two quadratic curves is usually discussed in collision detection problem between two coplanar objects.───平面实体间的碰撞检测中，经常需要讨论二次曲线间的位置关系。