Answer:
Does your bio textbook show you?
The saliva has enzymes that start to break down food using the lock and key system.The teeth chews the food and begins mechanical break down of food
An example of force that acts at distance is gravity and an example of contact force is pushing a chair across the room
<span>They exhibit all the stages when its the presence of oxygen only.</span>
<span>The circulatory, immune, skeletal, excretory, muscular, endocrine, digestive, nervous and respiratory. those are the eight systems of the human body.</span>
