Answer the following question given this paragraph: 

16.3 Circulatory and Respiratory Systems Animal respiratory systems are designed to facilitate gas exchange. In mammals, air is warmed and humidified in the nasal cavity. Air then travels down the pharynx and larynx, through the trachea, and into the lungs. In the lungs, air passes.


Q: In mammals, air is warmed and humidified in what?


A:
nasal cavity