Why do we sneeze when we inhale a lot of dust-laden air? [3 MARKS]

Each point: 1 Mark

1. When we inhale dust-laden air, dirt particles enter the nostrils.
2. Sometimes they get past the nostril hair in the nasal cavity and irritate the lining of the cavity. As a result we sneeze.
3. Sneezing expels these foreign particles from the inhaled air and a dust free, clean air enters the body.