What are correct examples of physical (P) chemical (C) biological (B) barriers

the cost of mining is extremely low compared to the money earned from mining, creating income to improve the environment.

if you know your abc's you should be able to get your answer or just use google

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.