露营车的黑水箱需要定期清理。

The camping trailer's ___blackwater tank should be cleaned regularly.

这片沼泽的黑水因腐烂的植物而呈现出深褐色。

The ___blackwater in this marsh appears dark brown due to decaying plants.

这家黑水公司在战区提供安保服务。

This ___blackwater company provides security services in war zones.