Answer:
the oxygen concentration decreases only when the air reaches the alveoli, which are the terminal branches of the respiratory system
Step-by-step explanation:
The human respiratory system is responsible for taking in oxygen-rich air, and they expelling oxygen-poor air. The respiratory system consists of lungs, which helps in the exchange of gases: Oxygen and carbon dioxide.
The statement ''the oxygen concentration decreases only when the air reaches the alveoli, which are the terminal branches of the respiratory system'' explains the change in oxygen concentration of the inspired air