Give suitable explanations for the following:

(i) One should breathe by nose and never by mouth.

(ii) Hands must be washed before eating food.

(iii) Eating places must be kept free of flies.

(i) One should breathe by nose and never by mouth because nose contains hair and mucous to trap dust and micro-organisms, so that the inhaled air becomes pure and the respiratory passage is free of dust and micro-organisms.

(ii) Washing hands before eating food is essential because our hands come into contact with various objects and surfaces throughout the day, many of which can carry harmful germs. These germs which may be picked up by our fingers and transferred to other parts of our body or into the mouth through food. Thus, washing hands helps protect us from diseases that can be transmitted through these germs or vectors.

(iii) Flies contaminate our food in various ways like by sitting on it, pouring out its saliva on it, depositing its excreta on the food while it feeds and so on. Hence, to avoid contamination of food and prevent the spread of diseases, eating places must be kept free of flies.