John observed bacteria at 100X under the oil immersion and then decided to go back to 40X objective by raising the oil objective a little to avoid the damage to objective lens. Critique his technique

well, i believe that the answer is 2. : 3

your answer is going to be physical weathering

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.