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.
Best Answer: In general, the lungs. But the respiratory system starts at the nose and mouth and ends at the cells of the body. Oxygen is inhaled though the nose/mouth down through the trachea into the lungs down to the air sacs. Then the oxygen will transfer to the blood stream and be taken around the body to all the little cells that need it. All are important for the body to stay alive.