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

Example Input: Mesoderm type of cell layer do flatworms have.
Example Output: What type of cell layer do flatworms have?

Example Input: Most of the gray matter is on the surface of the brain, surrounding white matter.
Example Output: Most of the gray matter is on the surface of the brain, surrounding what other type of matter?

Example Input: Warm water from the equator mixes with cold water from the poles.
Example Output:
Warm water from the equator mixes with cold water from where?