Detailed Instructions: Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
See one example below:
Problem: Earth rotates on its axis once times in one day.
Solution: How many times does Earth rotate on its axis in one day?
Explanation: The given output correctly poses a question based on the scientific fact given.

Problem: The lens of the eye is a(n) convex shape.
Solution:
What shape is the lens of the eye?