In this task, you are given a question and an answer, you would be asked to create the sentence based on the Question-Answer provided. It should be contained within the Question-Answer provided.

Q: Question: The pleura that surrounds the lungs consists of how many layers? Answer: two

A: The pleura that surrounds the lungs consists of two layers.
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Q: Question: What system consists of neurons that carry signals to skeletal muscles? Answer: motor system

A: The motor system consists of neurons that carry signals to skeletal muscles.
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Q: Question: What play an important role in the modulation of the nuclear chain reaction? Answer: control rods

A:
Control rods play an important role in the modulation of the nuclear chain reaction.
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