i believe the answer is "A fundamental role". hope this helps.
D oxygen there was no free oxygen on the earth
Every action has an equal and opposite reaction. I would assume that the energy in the other direction would be an action.. though I'm not entirely sure. I hope it helps.
Mountains determine wind flow, as well as serving as a cloud break. Depending on which side of the mountain you’re on, you will either have a mostly dry, dead region. Or a moist, fertile region.
