Arrange the following in the decreasing order (most important first) of their importance, for the welfare of human society. Give reasons for your answer.

Biogas, Citric acid, Penicillin and Curd


The importance of substances in decreasing order is


Pencillin, Biogas, Curd and Citric acid


Pencillin is an important antibiotic which helps in fighting against various bactaria; infections , hence , it is important for human welfare. Biogas is an eco friendly source of energy and helps in curbing pollution. Curd is a souce of Vitamin B12 and it has several benefits as food. Citric acid is used as a preservative in food industry.


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