The Cardiac Muscle contracts about 70 times per minute
I think the circulatory system is the best body system because we need the heart to stay alive, many people live with only one lung. but we need the respiratory system to let oxygen in, and let carbon dioxide out.
A lot of the army crew, if they have to make a trench they would have to send their men to the front line where there is gunfire.
<span>C. Alcoholics can stop drinking if they can admit that there is a problem.</span>
