TASK DEFINITION: Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
PROBLEM: Simple carbohydrates can be classified in terms of chain length.

SOLUTION: Which carbohydrates can be classified in terms of chain length?

PROBLEM: To determine the atomic weight of an element, you should add up protons and neutrons.

SOLUTION: How do you determine the atomic weight of an element?

PROBLEM: Stratus clouds occur in the low of the troposphere.

SOLUTION:
Where do stratus clouds occur in the troposphere?