Answer:
the answer is 'rectilinear propogation of light'
Explanation:
The nasal cavity is the hollow pipe (your nostril and upwards) that is covered with hairs and muscus membrane. Its main functions are to warm, moisturise, and filter air before it entering the body.
Hope it help :)
Puffin
Cell Theory #1: Cells are the basic structure and function of a living thing.
Cell Theory #2: All organisms (living things) are made out of cells.
Cell Theory #3: Only existing cells can make new cells.