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.
Respiratory System The Respiratory System The Respiratory System supplies the blood with oxygen in order for the blood to deliver oxygen to all parts of the body. The Circulatory System The Circulatory System transports blood and oxygen from the lungs to tissues in the body.iaphragm The lungs are a very important part of the respiratory system. They bring oxygen into the body and remove carbon dioxide. The bronchioles are the main passageway into the lungs in the bronchus. The alveoli is an air cell of the lungs.