Answer: Definition
Explanation: In science, the word 'theory' refers to the way in which people interpret facts. A scientific theory is the framework for observations and facts. Theories may change, the way in which they are interpreted may change, but the facts remain the same.
Respiratory- You breath faster to help supply the muscles with more oxygen.
Integumentary (skin) - Sweat helps cool down the body.
The brain recieves stimuli. Your brain does a lot of things for you. It is one of the busiest organs in your body. Your brain stimulis can enjoy various brain stimulis games to keep your brain healthy and sharp. if it stays healthy, everything follows after.
Explanation:
The modern theory of chemical evolution is based on the assumption that on a primitive earth a mixture of simple chemicals assembled into more complex molecular systems, from which, eventually came the first functioning cell(s).
Something people think is true is C.Belief
