Give any four factors necessary for a healthy person.

(1) Environment. (i) A clean physical environment with the help of public health services. (ii) A congenial social environment.
(2) Personal hygiene. Personal cleanliness prevents catching up of infectious diseases.
(3) Nourishment. Intake of a proper balanced diet keeps the immune system strong.
(4) Vaccination. -Timely vaccination against major disease (e.g., polio, T.B., chicken pox, etc.) protects one self from catching those diseases.