Answer:
I think it's D, but it could be B.
Explanation:
<span>I believe the answer is: D. proteins
The main functions of these proteins is to allow specific substance to pass through the membrane of the cells which needed for the energy formation for cells'functions.It created through the combination of more than 20 amino acids with different functions.</span><span />
The correct answer is a theory.
A theory is a rational and contemplative kind of generalizing or abstract thinking or the outcomes of such thinking. On the basis of the context, the outcomes might involve generalized illustrations of how nature functions.
A theory can be a source of knowledge that may or may not is related to the specific explanatory models. To theorize is to create the body of knowledge.
The answer is the nasal cavity. It is a large air filled space above and behind the nose in the middle of the face, it is lined with hairs and mucus membrane. The function of the nasal cavity is to warm, moisturize, and filter air entering the body before it reaches the lungs.
