Question

select the correct answer from each drop - down menu.
why are biogeochemical cycles important?
earth is a closed system. that means the amount of rocks, metals, carbon, nitrogen, oxygen, and water on earth
so, it is essential that biogeochemical cycles these materials as they move through
earths subsystems

Explanation:

Earth is a closed system, so the amount of essential materials like rocks, metals, carbon, nitrogen, oxygen, and water is fixed. Biogeochemical cycles are crucial as they renew these materials as they move through Earth's subsystems. If they didn't renew, the materials would be depleted in one subsystem and unavailable in others. Destroying or creating these materials (in the context of Earth's closed - system nature for these substances) is not the case.

Answer:

The first blank is "is fixed" (assuming it's a drop - down option related to a fixed amount as Earth is a closed system). The second blank is "renew".