instruction:
Given a scientific question, generate a correct answer to it.
question:
Which human body system is a complex network of nervous tissue that carries electrical messages throughout the body?
answer:
the nervous system

question:
While in the lungs, blood gives up carbon dioxide and picks up what element before returning to the heart?
answer:
oxygen

question:
What process refers to a separation of charge within an atom or molecule?
answer:
polarization