Why do people sneeze?
When something foreign gets in your nose, you sneeze so it won't get into your lungs. It's an automatic response. Your nose is like a filter for your lungs. That is a way to simple and not scientific answer but I think it gets the point across.
dust particles possibly
por que sim :s
Irritation to the nose.
so they dont have to look at your face
i think dust or something like that got in their nose and they are getting it out
To expel the cancer.
When something tickles or bothers your nose I guess