The tropic chain in modern cities has long been severed, and organic fertilizers, once cherished by peasants, have become urban disasters, polluting our rivers and lakes.

完整的营养链在当代城市生活中早已被切断，被农民当作宝贝的有机肥料，而今变成了一种城市灾害，对河流湖泊造成了污染。