The answer is B, carbohydrates.
Carbohydrates are the first choice of the energy source of your body, they can be broken down into simple and soluble compounds such as glucose. These can be used by cells for respiration to generate energy for activities such as growth, movement, repair etc. Besides using for respiration, they are also capable of forming cell structures such as cellulose.
B. because they are not manufactured by the body
Thin coat , becaus eit protects from temperature
“No man is an island.”This saying is also true for organisms in an ecosystem. No organism exists in isolation. Individual organisms live together in an ecosystem and depend on one another. In fact, they have many different types of interactions with each other, and many of these interactions are critical for their survival.
