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

Example Input: A collapsing nebula leads to nuclear fusion process.
Example Output: A collapsing nebula leads to what process?

Example Input: A concave lens is thicker at the edges than it is in the middle.
Example Output: What type of lens is thicker at the edges than it is in the middle?

Example Input: The values of strangeness assigned to various particles are based on decay systematics.
Example Output:
The values of strangeness assigned to various particles are based on what?