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.
Components of the respiratory system. The human body needs a constant supply of oxygen to enable energy to be released. Breathing is the means by which this is done and the process is known as respiration.The respiratory system brings air (with oxygen) into the body and removes carbon dioxide from the body. Air passages.A series of air passages allow air and the oxygen it contains to be transferredto the blood stream and also remove waste products.omponents of the respiratory system. The human body needs a constant supply of oxygen to enable energy to be released. Breathing is the means by which this is done and the process is known as respiration.