Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
One example is below.
Q: Earth rotates on its axis once times in one day.
A: How many times does Earth rotate on its axis in one day?
Rationale: The given output correctly poses a question based on the scientific fact given.
Q: Topsoil layer of soil, essential for farming, has the highest proportion of organic material.
A:
What layer of soil, essential for farming, has the highest proportion of organic material?