Answer:
a gradual increase in the overall temperature of the earth's atmosphere generally attributed to the greenhouse effect caused by increased levels of carbon dioxide, chlorofluorocarbons, and other pollutants.
Explanation:
A- on the sides you would find the phosphate and sugar so the center is the AT or CG
the internal structures provide shapes and support to a variety of living organisms both unicellular and multicellular
I believe that the answer is B.
