The answer for the first question is B. mucus sweat and tears, all of those are defenses that the body uses when attacked. Now for the second option is A the answer because the first filter that a virus or a desease must pass is indeed the skin. Hope is good for you
Answer:
black carbon which is "B"
Answer: A. Environmental drivers plus genetic variation in the population result in natural selection
Explanation: over geological time environmental conditions change. Organisms do not survive in one environmental niche with traits adapted to a possible future change that might suit those traits. Adaptation is not a matter of choice: adapt if possible or go extinct.
There is a (badly named) concept called pre-adaptation, which is that variations in some existing trait render adaptation to a different environment more likely.
A compound is organic if it contains carbon covalently bonded to other atoms. Most often, the other atoms include hydrogen, oxygen, and/or nitrogen. A few carbon compounds, such as simple oxides (e.g. CO2) and cyanides (e.g. KCN) are excluded arbitrarily.
