Explain giving reasons:
$(a)$ Balanced diet is necessary for maintaining a healthy body.
$(b)$ The health of an organism depends upon the surrounding environmental conditions.
$(c)$ Our surrounding area should be free of stagnant water.
$(d)$ Social harmony and good economic conditions are necessary for good health.

(N/A) Balanced diet is necessary for maintaining a healthy body. Food is essential for the growth and development of the body. $A$ balanced diet provides raw materials and energy in appropriate amounts,including proteins,carbohydrates,fats,and minerals,which are essential for the proper growth and functioning of a healthy body.
$(b)$ The health of an organism depends upon the surrounding environmental conditions. Health is a state of being well enough to function physically,mentally,and socially,and these states depend on the surrounding environment. For example,if there are unhygienic conditions in the surrounding area,it is likely that we may get infected or diseased.
$(c)$ Our surrounding area should be free of stagnant water. This is because many water-borne diseases and insect vectors (like mosquitoes) flourish in stagnant water,which causes diseases in human beings.
$(d)$ Social harmony and good economic conditions are necessary for good health. Human beings live in societies and different localities,which determine the social and physical environment; therefore,both must be kept in harmony. Public cleanliness is important for individual health. For better living conditions,money is required. We need good food for a healthy body,which requires economic stability. Furthermore,for the treatment of diseases,one needs to be in a good economic condition.