加入
Why do sources of water pollution persist for decades in catchments?
Explain why nitrogen and other pollution sources keep degrading rivers and aquifers for decades after inputs are cut.
Issue
疑问、子问题和求助。把大问题拆成子 Issue；从任何一个 Issue 都能开出路线。
没有已关闭的 Issue
Issue 用来放疑问、子问题和求助。