TASK DEFINITION: Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
PROBLEM: Very low density is the concentration of gas molecules in the mesosphere.

SOLUTION: What is the concentration of gas molecules in the mesosphere?

PROBLEM: Half-life property of carbon and other elements can be used to date fossils and rocks, among other things.

SOLUTION: What property of carbon and other elements can be used to date fossils and rocks, among other things?

PROBLEM: The visceral senses are most often below the limit of conscious perception because they are involved in this?

SOLUTION:
The visceral senses are most often below the limit of conscious perception because they are involved in this?