UPSC 2013 CDS 2 GK Paper

Among the given items, Cowdung, paddy-husk and vegetable wastes are groups of items that contains only biodegradable items.Biodegradable items are capable of being broken down (decomposed) rapidly by the action of microorganisms. Biodegradable substances include food scraps, cotton, wool, wood, human and animal waste, manufactured products based on natural materials (such as paper, and vegetable-oil based soaps).