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: A frog develops (a/an) lungs as it changes from a tadpole to an adult frog.

Answer: Which of the following structures does a frog develop as it changes from a tadpole to an adult frog?


Question: The brain is the most complex organ in the human body.

Answer: What is the most complex organ in the human body?


Question: Metabolism includes both anabolic and catabolic reactions.

Answer:
Metabolism includes both anabolic and which other reaction?