translation.en: Not that I'm a bad teacher, but I've been studying and teaching about human waste and how waste is conveyed through these wastewater treatment plants, and how we engineer and design these treatment plants so that we can protect surface water like rivers.
translation.zh: 不是因为我是一个坏老师， 而是我一直在学习和教授 关于人类排泄物方面的知识， 和这些排泄物是如何运达 污水处理厂， 以及我们是如何设计和建造 这些处理厂从而使得我们能够保护 像河水这样的地表水的。