12. answer: example: as the heart gets stronger, the heart likely will pump more blood with each beat. the heart will not need to work as hard to pump the same amount of blood. so, heart rate will likely decrease.
6. answer: the skeletal system provides the shape, supports and protects organs and the soft areas of the body. it's others functions are bodily movement, producing blood for the body, and storing minerals that the physical structure needs.
