Given a scientific question and its correct answer, generate supporting facts for the answer. This supporting fact can be an explanation for the answer to the given question.

Q: Question: What are the two main divisions of the human nervous system? Answer: central and peripheral

A: The two main divisions of the human nervous system are the central nervous system and the peripheral nervous system. The peripheral nervous system has additional divisions.
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Q: Question: What type of species can alternate between medusa and polyp forms? Answer: cnidarian

A: As you can see in Figure below , both body plans have radial symmetry. Some cnidarian species alternate between medusa and polyp forms. Other species exist in just one form or the other.
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Q: Question: A bicycle is an example of a compound machine made of many what? Answer: simple machines

A:
Arthropod at http://animal. discovery. com/animal-facts/arthropod-info. htm.
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