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: Blood is a important piece of the respiratory system as red blood cells carry oxygen around the body and is then extracted by the capillaries to be then provided to surrounding tissue. Not much of a paragraph, but if you do some research you'll be able to find more in-depth information.