TASK DEFINITION: Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
PROBLEM: Fractional crystallization is the separation of compounds on the basis of their solubilities in a given solvent.

SOLUTION: What is the separation of compounds on the basis of their solubilities in a given solvent?

PROBLEM: The discovery of ribozymes nullified the idea that all biological catalysts are proteins.

SOLUTION: What nullified the idea that all biological catalysts are proteins?

PROBLEM: Hydrocarbons compounds, which serve as fuels and are used in manufacturing, are called the driving force of western civilization.

SOLUTION:
What compounds, which serve as fuels and are used in manufacturing, are called the driving force of western civilization?