43. NCERT Exemplar XXIII

 

 

It is true that breathing through mouth may be harmful. Air contains some gases and dust particleswater vapour and dust particlesgases, water vapour and also dust particles. Air is inhaled through our nose because fine hair and mucusfine hairmucus present inside the nose helps to filter the gasespasses the dust particlesfilter the dust particles. It prevents them from getting into the respiratory systemcirculatory systemnervous system. It is not advisory to breathe through the mouth, because poisonous gasesharmful dust particlesharmless dust particles can easily enter in the body to affect our health.