Wich factor can cause secondary succession

Plzz hurry im being timed during times of vigorous physical activity, muscles require a constant supply of oxygen. how does the body respond to these needs? a. breathing rate and heart rate both decrease. b. breathing rate and heart rate both increase. c. heart rate decreases, but breathing rate remains stable. d. breathing rate increases, but heart rate remains stable.

Why do you suppose the structural polysaccharide cellulose does not contain branches?

List the substances normally stored in bone tissue