Digestion starts in the mouth when you're chewing, then the stomach, then small intestines.
Answer: 3.friction
Explanation: friction is a force of resistance acting between objects in contact and tending to dampen their motion
Usually under ground springs, or sometimes hollowed earth beneath solid earth where the water pools.
The folds in the stomach lining are called rugae. On these rugae, you will find a thin line of mucous which helps protect the stomach lining. The innermost layer is called Simple Columnar Epithelium.
