Question

which of the following are ways that phosphorus makes its way into the water supply?

none of these choices
decomposition and excretion
weathering and erosion
addition of fertilizers and runoff
all of these choices

Explanation:

• Decomposition and excretion: When organisms die, their bodies decompose, and phosphorus is released. Also, animal excretion contains phosphorus which can enter water.
• Weathering and erosion: Rocks containing phosphorus are weathered (broken down chemically or physically) and eroded (transported by wind, water etc.). The eroded material can carry phosphorus into water bodies.
• Addition of fertilizers and runoff: Fertilizers are rich in phosphorus. When it rains, runoff from agricultural fields (where fertilizers are used) can carry phosphorus - containing fertilizers into water supplies.

Answer:

all of these choices