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

Input: Consider Input: The water in some springs are hot because they're heated by hot magma.

Output: The water in some springs are hot because they're heated by what?


Input: Consider Input: A(n) gastropods is noted for having its eyes at the tips of stalks or tentacles that emerge from its head.

Output: What type of creature is noted for having its eyes at the tips of stalks or tentacles that emerge from its head?


Input: Consider Input: The cells in the follicle undergo physical changes and produce a structure called a corpus luteum.


Output: The cells in the follicle undergo physical changes and produce a structure called a what?