Oligopolists have an incentive to cheat on collusive agreements in order to:（）

A. avoid competitive practices.

B. restrain trade and hinder trade relationships.

C. increase their individual share of the joint profit.

各实验室在运送化学废弃物到各校区临时收集中转仓库之前，可以（）

A．堆放在走廊上

B．堆放在过道上

C．集中分类存放在实验室内，贴好物品标签