Oxygen.
Oxygen was fatal when organisms started using photosynthesis, this event was known as the Great Oxidation Event.
Answers should include three of the following ideas:
*The body needs exercise to eliminate wastes properly.
*Food poisoning can be prevented by cooking food properly and by sanitizing areas that come into contact with raw food.
*Some forms of functional dypepsia can be prevented by avoiding overeating, avoiding too many fatty foods, and chewing food adequately.
Thought and action are the two main functions
C because the muscular system is the only system in the body that moves
