A zone stays the same length, I zone and h zone get shorter
A covalent bond, also called a molecular bond, is a chemical bond that involves the sharing of electron pairs between atoms.
The answer is : ingestion and digestion
; propulsion and secretion
; absorption and elimination
Digestive system will receive and digest food to make the molecule smaller. After the molecule become small, it could be absorbed by the body. The waste that couldn't be digested and absorbed will be eliminated as feces. Some of the waste from the body like bilirubin would be dumped through feces too.
The most likely cause of the burning sensation is acid reflux which travels back up the esophagus and irritates the esophageal lining. The chest pain felt can feel almost like a heart attack but it is best described as referred pain from the esophagus.
Should this heartburn persist, it is highly recommended to see a physician because the acid can erode the esophagus lining & the abdominal lining leading to ulcers. Easily treatable condition.
From a personal level this is awful!