You need sleep to:

The addition of unwanted materials into the natural environment is:

The end product of composting of kitchen waste, garden trash etc, that forms the manure is:

The immediate help given to the victim before taking him to the hospital is:

The process in which reusable materials are remade into either the same product or new product.

A diet which contains all the nutrients required for the proper maintenance of health and optimum growth in correct proportion is called:

Protective food:

We should have only a limited intake of:

Who were the first people to record methods for treating water?

Body-building food or nutrient is: