Give one example mechanical digestion that takes place in the mouth

Mechanical digestion in the oral cavity consists of grinding of food into smaller pieces by the teeth, a process called mastication. Chemical digestion in the mouth is minor but consists of salivary amylase (ptyalin, or alpha-amylase) and lingual lipase, both contained in the saliva.

Only one reactant yields 2 or more products. meaning you will only have 1 product and it will break down into 2 or more products. eg. h2o -> h2 + o2

Sorry i dont understand the question can you rephase it?