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 is the system of respiratory passages, lungs and respiratory muscles of human body. Respiratory system is responsible for exchange of gases between the human body and the surroundings. In the process of exchange of gases, human body gains oxygen and gets rid of carbon dioxide.espiratory system is the system of respiratory passages, lungs and respiratory muscles of human body. Respiratory system is responsible for exchange of gases between the human body and the surroundings. In the process of exchange of gases, human body gains oxygen and gets rid of carbon dioxide.