Answer:
A. the cell membrane protects the cell
Explanation:
The question that is most likely to be studied by biologists could be "What is the effect of exercise on heart rate in horses?" since they study everything related to the Life. <em>Hope</em><em> </em><em>this</em><em> </em><em>answers</em><em> </em><em>your question</em><em>.</em><em>.</em><em> </em><em>And</em><em> </em><em>good</em><em> </em><em>luck</em><em>!</em><em> </em>
Answer:
d. sewage treatment and nitrous oxide
Explanation:
I would assume because of where san francisco is i suppose that it just depends on where your located at