Question

what is cilia and muscus

Answer 1

Cilia it is like hairs which also help in locomotion
Mucus it is a sticky material which prevent to enter the unwanted particles in our body.

Answer 2

The mucus traps any bacteria or pathogens as they enter the lungs and the cilla, located on the surface of ciliated epithelium move in a synchronised pattern to waft the mucus up the airway to the black of the throat where it can be swallowed and any pathogens can be killed by the acidity of the stomach