The atmospheric concentration of carbon dioxide has
varied over the past 400 000 years. For most of this time,
there was no industrial activity. Why, then, do we think
that the present increase in atmospheric carbon dioxide is
due to human activities?

the answer is c on e2020, bud.

answer: 20 percent

the fish culture has become a developing commercial practice in developing countries which is already prominent in developed countries of the world. the major fish protein demand is being supplemented in developing countries is   fishing to meet the needs of the growing population. therefore, in some developing nations, the percentage of animal protein from fish in the diet can be as high as 20 percent.