As we move past the relatively gigantic mammals, birds, frogs and plants to the more elusive insects and other small invertebrates and then beyond to the countless millions of organisms in the invisible living world enveloped and living within humanity?
从大型哺乳动物到鸟类到青蛙到植物 一直到昆虫以及其他非脊椎动物 再到无数的肉眼不可见的生物 ——它们就在人体内发展、生存