Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
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Question: Potential energy type of energy is possessed by autumn leaves before they fall.

Answer: What type of energy is possessed by autumn leaves before they fall?


Question: The endocrine system produces hormones to regulate growth, development, and reproduction.

Answer: Which human organ system produces hormones to regulate growth, development, and reproduction?


Question: Gas phase is pure chlorine present as.

Answer:
What phase is pure chlorine present as?