Question

a depression in the ground caused by the collapse of a cave or by the direct dissolution of limestone by acidic water is a(n)

Explanation:

A sinkhole is a depression in the ground. It can form due to the collapse of a cave (when the roof of an underground cave can no longer support the weight above it) or by the direct dissolution of limestone by acidic water (as acidic water reacts with limestone, gradually eroding it and creating a void that eventually collapses to the surface).

Answer:

sinkhole