农药可以杀灭害虫,但某些农药不易降解,容易在生物体内积累,农

农药可以杀灭害虫,但某些农药不易降解,容易在生物体内积累,农药逐级富集主要是通过

  A.空气    B.土壤    C.食物链    D.水

答案

C

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