... That your mouth produces 1 litre of saliva a day???!
*99% of saliva is water. The remaining 1% contains substances which are important for digestion, dental health and control of microbial growth in the mouth. (*taken from HERE)
Without saliva we would choke on our food and not be able to taste food.
Click on LINK and SALIVA to read more about the human saliva and its role and function.