Answer:
the third one
Explanation:
physical change is only on looks
Answer:
Cartilage rings of trachea have protective role
Explanation:
Trachea is a tube, part of the respiratory system, which allows the passage of the air: from larynx to lungs (primary bronchi). It is enveloped with cartilage rings that prevent collapse of the trachea when there is no air. The cartilage "rings" are C-shaped, except one full ring-shaped - the cricoid cartilage which attaches trachea to the larynx.
The most important acid deoxyribonucleic acid, or DNA, which carries the genetic code of any organism it, and the way that it transmits the individual characters in the life without this acid, or genetic code world would not exist :)
I hope you understand what I mean :)