Things in motion tend to stay in motion, things at rest tend to stay at rest. Your brain never slowed down to the point where it would get tired to sleep. If you were laying in bed trying to sleep all night but couldn't that could be a medical disorder but if you were doing things you're fine
To define or explain something again in a different way.
Example: Learning that he had been adopted forced him to completely redefine his identity
Different genes control the development of different characteristics of an organism.
I'm pretty sure the answer to this question is choice D.
