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

Input: Consider Input: Line graphs are especially useful for showing changes over time.

Output: Line graphs are especially useful for showing changes over what?


Input: Consider Input: Seismic waves prove the inner core it is solid.

Output: What do seismic waves prove about the inner core?


Input: Consider Input: Snakes use their tongue to smell things.


Output: What do snakes use to smell things?