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

Q: Age causes reduction of elasticity in all organs.

A: What causes reduction of elasticity in all organs?
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Q: Mesoderm type of cell layer do flatworms have.

A: What type of cell layer do flatworms have?
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Q: Carbon-based compounds are the most common types of compounds found on earth.

A:
What are the most common types of compounds found on earth?
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