TASK DEFINITION: Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
PROBLEM: The mitochondria organelles are known as the "power plants" of the cell.

SOLUTION: What organelles are known as the "power plants" of the cell?

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: 22 million many people die from air pollution each year.

SOLUTION:
How many people die from air pollution each year?