instruction:
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.
question:
Question: What system consists of neurons that carry signals to skeletal muscles? Answer: motor system
answer:
The motor system consists of neurons that carry signals to skeletal muscles.


question:
Question: Which kind of muscle regulates air flow in lungs? Answer: smooth
answer:
Smooth muscle regulates air flow in lungs.


question:
Question: Exposure to what can increase the amount of pigment in the skin and make it appear darker? Answer: ultraviolet radiation
answer:

Exposure to ultraviolet radiation can increase the amount of pigment in the skin and make it appear darker.