Question

give reason - The inner wall of nostrils are lined with hair and mucus

Answer 1

Cilia or small hairs which project from the epithelium and line the nasal mucosa create motions which drainmucus from the nasal passage to the throat from where it is swallowed and digested by stomach juices. ... Mucusmay accumulate in and drip from thenostrils (runny nose) in these conditions.

Answer 2

They are meant to protect our lungs from allowing foreign particles like pollen dust, allergen etc., and they are rarely blown out by sneezing