Why do some children fall ill more frequently than others living in the same locality?

OR

Give any four factors necessary for a healthy person.

Following can be the reasons for some children falling ill as compared to others living in the same locality-

(a) Lack of balanced diet

(b) Unavailability of clean drinking water

(c) Poor hygiene

(d) Absence of vaccination

(e) Less developed immune system

OR

(a) The surrounding environment should be clean. Air and water-borne diseases should not spread.

(b) Personal hygiene prevents infectious diseases.

(c) Proper, sufficient nourishment and food is necessary for good immune system of our body.

(d) Immunization against severe diseases.