Question

carbon that is underground in the form of fossilized animals cannot be used in the carbon cycle unless humans extract it from the ground. when an element is stored in a part of the carbon cycle, what do we call it?
a nutrient sink
gone forever

Explanation:

In the carbon - cycle, when an element is stored in a part of it, it is called a nutrient sink. A nutrient sink is a reservoir that accumulates and stores a particular nutrient or element. It is not "gone forever" as elements in sinks can be re - introduced into the cycle under certain conditions.

Answer:

a nutrient sink