Question

what do the mitochondria do? they store food and water. they let things in and out of the cell. they power the cell.

Explanation:

Mitochondria are known as the power - houses of the cell. They generate most of the cell's supply of adenosine triphosphate (ATP) through cellular respiration, which is used as a source of chemical energy. Storing food and water is the function of vacuoles, and the cell membrane controls what enters and exits the cell.

Answer:

They power the cell.