What does an electrocardiogram measure? a) sound waves created by the closing of heart valves b) the volume of blood moving through the heart chambers c) the force of muscle contraction in the heart chambers d) action potentials moving through the heart muscle

trachea, alveoli, lung capillaries, arteries

the main thing i would use is bricks because if there is a hurricane, there is a great possibility for the house to still stand. and i would also use plexiglass windows instead of regular windows because plexiglass isn't prone to breaking.