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

Example Input: Mercury is not a solid even at room temperature.
Example Output: Which metal is not a solid even at room temperature?

Example Input: Aerobic exercise helps improve the cardiovascular system, while anaerobic exercise causes muscles to get bigger and stronger.
Example Output: Aerobic exercise helps improve the cardiovascular system, while what exercise causes muscles to get bigger and stronger?

Example Input: Cyclins regulate the cell cycle only when they are tightly bound to cdks.
Example Output:
What regulates the cell cycle only when they are tightly bound to cdks?