Answer to Question 1
C
Answer to Question 2
The soils that are overfertilized become depleted in nutrients and less fertile,
demanding more fertilizer. Also, runoff brings the applied chemicals into groundwater and
streams, where it can be ingested by humans. The phosphorus and nitrogen compounds
have been shown to have effects in humans in large quantities, and it is not known what
effects of exposure to small concentrations will be.