The pneumatic bones are important to birds for respiration. They are hollow bones which are connected to the bird's respiratory system and are important for birds to be able to breath. Examples of pneumatic bones are the skull, humerus, clavicle, keel (sternum), pelvic girdle, and the lumbar and sacral vertebrae.
<span>Rh-positive fetus and an Rh-negative mother condition occur.</span>
"simple aerobic bacteria"relating
to or denoting exercise that improves or is intended to improve the
efficiency of the body's cardiovascular system in absorbing and
transporting oxygen.