When diving doubles you will need to use your wing/BCD to compensation. Typically you can't control your buoyancy only with a drysuit with steel doubles and stage bottles so you will need to use your wing to offset buoyancy.
The structure of the throat is designed to prevent food from entering the lungs. Photo Credit matthewennisphotography/iStock/Getty Images. When food enters the lungs instead of the esophagus, it affects breathing and can cause choking and other problems.
The epiglottis covers the opening to the trachea when swallowing - thereby preventing food/drink entering the trachea and lungs. There are three kinds of answers: ones that are mostly right, ones that are mostly wrong, and those that once were right but now are wrong.