1 An unopened container should last for 1-3 months at 40Â°F or less in the refrigerator, but some companies guarantee their product for up to 6 months.  If left in its partially-open original paper wrap, the exposed area of stick butter will begin to harden and smell stale after about a week, as oxygen sets in.
Quick Answer. Humans need a respiratory system because it is made up of organs that allow them to breathe. Breathing delivers oxygen to the body and takes away carbon dioxide. Every cell in the body needs oxygen to obtain energy from food. Continue Reading.
MAJOR HUMAN BODY SYSTEMS. Respiratory System Your respiratory system provides the energy needed by cells of the body. Air is breathed in through the nasal cavity and/or mouth and down through the throat (the pharynx). The throat has three parts-the nasopharynx, the oropharynx, and the laryngopharynx.our digestive system consists of organs that break down food into components that your body uses for energy and for building and repairing cells and tissues. Food passes down the throat, down through a muscular tube called the esophagus, and into the stomach, where food continues to be broken down.