Answer:
The correct answer is They warm and moisten the air.
Step-by-step explanation:
The respiratory system is responsible for absorbing oxygen from the air and expelling all substances that harm the body. He is responsible for the transport of gases that occurs in the circulatory system.
When the air enters our body it does so in a hot and humid way and that is how it reaches our lungs. The air enters through the nasal passages, which are covered with cilia that also remain moist thanks to the mucous secretions.
The function of the cilia together with the mucous secretions is to filter the particles of solid air and heat and humidify the air. Keeping the air moist prevents the lungs and other parts of the respiratory system from drying out.
That is why it is very important to always try to breathe through the nose and not through the mouth.