Why should a scientist conduct library research before beginning an experiment?

Before starting any experiment, the scientist must study each and every thing related to that particular experiment.

In order to conduct an effective experiment, the scientists must study the researches done in the past. Also, he or she should study the outcome and interpret the results in order to gain more knowledge and factual information.

Reading about various researches also allows interpreting the probable mistakes during the experiment. All these factors, enhances the chances of obtaining a good result. Hence, the scientist must conduct a library research before beginning a new experiment.  

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.