The circle part about the circulatory sysytem
Given that Sheena's ball is a sphere, its volume can be obtained by using the formula: V_ball = (4/3)*pi*r^3, where, r is the radius of the sphere. Since the ball is 24 cm across, this means that the radius is half of the diameter which is equal to 12 cm. Thus, the volume of the ball is equal to 7238.2295 cm^2.
The bronchi (singular: bronchus) are the airways that lead from the trachea into the lungs, and then branch into smaller bronchioles. Structurally, the bronchi are made up of cartilage that gives them stability and prevents their collapse.