The American black bear lived during the same period as short-faced bears (Arctodus simus and A. pristinus) and the Florida spectacled bear (Tremarctos floridanus). These Tremarctine bears evolved from bears that had emigrated from Asia to North America 7â8 ma.
A plenum space is a part of a building that can facilitate air circulation for heating and air conditioning systems, by providing pathways for either heated/conditioned or return airflows, usually at greater than atmospheric pressure.
A plenum chamber is a chamber that operates at a positive pressure  and is filled with fluid or air. It is used to increase air flow in  enclosed spaces. The positive pressu â¦ re draws air from the space  into channels, which causes air movement.he pumping chambers are the lower two chambers, the ventricles. The right ventricle pumps blood to the lungs, and the left ventricle pumps blood to the body through the aorta â¦ . The ventricles are the pumping chambers'.