I believe it is azotemia.
<span>Proteins are composed of __20__ amino acids, of which __9__ are essential amino acids and __11__ are nonessential amino acids.</span>
The answer is D, moist skin surfaces.
Explanation:
Cnidaria and flatworms respirate and extreme through their skin via diffusion.
Answer: Cnidarians have a very simple sensory system that consists of a nerve net and no sensory organs. Octopi have a complex sensory system, including a brain and eyes as complex as human eyes.
(Here are two examples. Hope this helps!)