The dependant variable would be the salmon, because they depend on the water and pollution levels to give a result.
C it will be c because earth has water
Answer:
The Mississippi river water source is fed by Lake Itasca in Northern Minnesota.
Solar energy provides the reducing power within green leaves to convert CO2 and H2O into sugars. ... During illumination, leaf cells have both a source (respiration) and sink (photosynthesis) for CO2. Respiration in some species appears to be greatly stimulated by light.