purity has a yes opposites on the marbles / land good / land good / type & runoff from a cropland causes water pollution ->  runoff from cropland has a negative impact on water quality  runoff from cropland has a negative impact on water quality & a lake is a kind of body of water & runoff is when cropland water enters bodies of water -> nutrients from a cropland leave a sea has a yes wire on land good in that sea runoff from a cropland entering a lake has a negative impact on water quality in that lake  runoff from a cropland entering a lake has a negative impact on water quality in that lake & land is a mean of artificial eroding -> runoff from a cropland entering a lake has a negative impact on a natural resource by having a negative impact on water quality