Given scientific fact as input, generate the question from this fact such that it can be answered from the input.

Example Input: The sun delivers power to the chemical factory chloroplasts.
Example Output: What delivers power to the chemical factory chloroplasts?

Example Input: The mitochondria organelles are known as the "power plants" of the cell.
Example Output: What organelles are known as the "power plants" of the cell?

Example Input: Because action potentials are so brief, a neuron can produce hundreds per second.
Example Output:
Because action potentials are so brief, a neuron can produce hundreds per what?