translation.en: We use open pond systems. Now, around the world they are growing algae, with this racetrack design that you see here. Looks like an oval with a paddle wheel and mixes really well, but when it gets around the last turn, which I call turn four — it's stagnant.
translation.zh: 我们用开放式水塘系统 目前在世界上 人们用这种跑道设计来种植藻类 如图，看起来就像 带桨的椭圆，而且混配得还不错 但当它来到最后一步时 我称之为第四步——它就停滞了