The blood circulates, so blood is reused constantly. There's no break in the circle, so it is a closed system
When a person is exercising the blood is shifted from skeletal muscles into the systemic circulation. Skeletal muscle is one of the three major muscle type the other two is smooth muscle and cardiac muscles. Most most the skeletal muscle is attached to the bones by tendons.
Answer:
It should be D.
Explanation:
The invasive species will negatively effect the ecosystem and the natural predator in the area. Like the Blue Lobster problem in Maine.
