Answer:
A Protein
Explanation:
muscles Need Protein To work just like liver
A. the respiratory system involves the lungs and airway, that is bringing the oxygen in and releasing the carbon dioxide
Infection with a pathogen does not necessarily lead to disease. Infection occurs when viruses, bacteria, or other microbes enter your body and begin to multiply. Disease occurs when the cells in your body are damaged as a result of infection and signs and symptoms of an illness appear