An assumption or conclusion that is rationally and logically made, based on the given facts or circumstances. An inference is based off of facts, so the reasoning for the conclusion is often logical. Before she was weighed at the gym, Jill made an inference about Susan's weight based on her knowledge of Susan's eating and workout habits..
The first task of the digestive system is to break down food into a fine pulp (mechanical digestion). When the food is physical broken down, digestive chemicals break the food down into small molecules (chemical digestion). The mouth is the organ in which the process of digestion begins. It starts the process of mechanical digestion by grinding the food with teeth. Also in the mouth, an enzyme called salivary amylase begins to break down long starch molecules into maltose.
The mouth begins the digestive process. Food entering the mouth is chewed using the teeth. The chewing process is also known as mastication. Chewing uses muscles in the mandible (lower jawbone) to close the lower jaw against the upper jaw. These muscles are very strong, capable of crushing relatively hard food.