How do some cells become brain cells and some skin cells?

This is giving me a headache i have asked others and they don’t know it either

We can plant more trees and plants.

The need activity of the nurse is to suction discharges from the trachea. current treatment approaches in the pressing consideration facilities or crisis offices are corticosteroids and nebulized epinephrine; steroids have demonstrated advantageous in extreme, direct, and even gentle croup. in the clear instances of croup, anti-microbials are not endorsed, as the etiology is viral