Your body used the respiratory system (lungs)
The capability of both leptin and cholecystokinin in which they
have a similarity when a person has decreased its food intake. A leptin is a
way of helping an individual to regulate energy in means of having to inhibit
its hunger while the cholecystokinin is responsible for having to stimulate
digestions.
Your outer skin is your epidermis, so just look at your arm
It's an Agrarian society, hope this helps!
I'll say C, Science cannot answer difficult question...let me know.
