Answer:
The return of blood to the heart is assisted by the action of the skeletal- muscle pump. As muscles move, they squeeze the veins running through them. Veins contain a series of one-way valves, and they are squeezed, blood is pushed through the valves, which then close to prevent backflow.
I can't answer 1 but 2=First, make sure you weather proof the house, than go from there and try anything you think is necessary in this situation.
The correct answer is D. 10%