translation.en: So what are microalgae? Microalgae are micro -- that is, they're extremely small, as you can see here a picture of those single-celled organisms compared to a human hair.
translation.zh: 那么什么是微藻呢？微藻是微小的东西 非常非常小，正如你们现在看到的 单细胞生物体——微藻 与人类毛发的对比图