Why do we sneeze

The change in Gibbs function during gas movement gas molecules move from high pressure to low 

When we sneeze, the gases contained in the lungs are ejected through the throat so violently that they can move at extraordinary speeds of well over a hundred miles an hour. One of the obvious reasons for a sneeze is to expel germs, dust, etc. in the nose - which is why a sneeze can be so messy. 

It is relatively easy to unblock a nose by blowing, but a sneeze is a superb means for unblocking the nose from the opposite direction. 

The air pressure above the upper side of the paper decreases because the air moves over its surface faster than the air stream running past the paper s underside. The 

Partial vaccum here causes paper to lift 

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