The process begins in the mouth as we chew food and saliva acts upon it, beginning the breakdown of starches into sugars.
(The process; begins; L:in the mouth; T:as we chew food and saliva acts upon it) (we; chew; food and saliva acts upon it)
The process we
begins chew
L:in the mouth T:as we chew food and saliva acts upon it
food and saliva acts upon it