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: The respiratory tract is important in humans because the body's cells need oxygen in order to survive. The respiratory system consists of the pulmonary arteries, pulmonary veins, lungs, trachea, bronchioles, and the alveoli. All these components work together in order to oxygenate the tissues of the body.