Give two functions of the nasal cavity?

The nasal cavity is part of the Olfactory System, which is one of the 5 senses and is the sense of smell. It works closely with our sense of taste.

Another function of the nasal cavity is to warm and moisted the air as we breath in. That is why we are told that we should breath in through our noses and out through our mouths. On a very cold day, we may do this automatically without realising.

Hope this helps.