Helpzzz Explain how physical variation is expressed in human beings and how it relates to culture groups and ethnicity?

Imagine ? person stepping on a pin and pulling his or her foot way look at the réfléchir arc of the scenarios below

Kelly ran electricity though a sample of water using electrolysis. the water changed into two gases, x and y. it was not possible to break down the gases x and y into simpler particles.

Isolated volcanic peaks on the ocean floor are