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.
Well, these are two completely different systems. The Respiratory system is the system of your body that deals with the exchanges of gases in your body, such as oxygen and carbon dioxide (waste from your cells). The Circulatory system deals with circulating blood throughout your body. However, even though these are two different systems, they are vital to each other. Your heart (Circulatory) and your lungs (Respiratory) are vital to each other. The blood in your body needs oxygen to produce energy in your body. The only way to obtain such is through the Respiratory system.