give reasons:-

1) balanced diet is necessary for maintaining healthy body.

2) health of an organism depends upon the surrounding environmental conditions.

3) our surrondings area should be free of stagnant water.

4) social harmony and good economic conditions are necessary for good health.

1) Balanced diet is necessary for maintaining healthy body. This because healthy food provides the body stamina to fight back the diseases and it also helps in recovering from disease.

2) Health of an organism depends upon the surrounding environmental conditions. If surroundings are not clean and there are piles of garbage or stagnant water than it will provide breeding place to many mosquitoes and disease causing pathogens which will spread the disease in the locality and affect the health of the organism. 

3) Our surroundings area should be free of stagnant water as stagnant water is a breeding place for mosquitoes and flies which acts as the vectors of many diseases.