Answer: B. under use; it is a scarce resource.
Explanation:
Early settlers in the town of Dry Gulch drilled wells to pump as much water as they wanted from the single aquifer beneath the town. (An aquifer is an underground body of water.) As more people settled in Dry Gulch, the aquifer level fell and new wells had to be drilled deeper at higher cost.Residents of Dry Gulch have a private incentive to under use water because it is a scarce resource.
Answer:
I believe it is receptors
Mars is just a fraction the size of the Earth, so it cooled more rapidly. And as it cooled, its molten iron core hardened. As a result, Mars stopped generating its magnetic shield. And, according to one theory, this left its atmosphere to be scoured away by the solar wind.