论坛管理员会确保每个讨论都保持礼貌和有序。

The ___moderator ensures every discussion remains polite and orderly.

辩论赛的主持人确保了每位选手都有平等的发言时间。

The ___moderator of the debate ensured each speaker had equal time to present.

这种化学物质用作反应的调节剂，可以控制反应速度。

This chemical acts as a ___moderator to control the reaction speed.