Biogeochemical cycles on Earth serve a variety of different purposes. What do the biogeochemical cycles have in common?
AThey all serve the same function in sustaining life on Earth.
BThey all include only nonliving components of an ecosystem.
CThey are all essential for sustaining life on Earth.
DThey all include only living components of an ecosystem.
AThey all serve the same function in sustaining life on Earth.
BThey all include only nonliving components of an ecosystem.
CThey are all essential for sustaining life on Earth.
DThey all include only living components of an ecosystem.