average molecular kinetic energy in a substance
O positive is the most common blood type and most likely to be transfused.
O negative donors are the “Universal Donor.” People with O negative blood are universal red blood cell donors. This means that their red blood cells can be transfused to any blood type.
The bark of a tree is impervious to gases and water because bark cells are dead cells of the epidermis and compactly arranged without intercellular spaces. They contain a chemical called suberin in their walls that make them impervious to gases and water and it doesn't allow gases or water into the tree as bark cells are in the bark outer most layer of the tree.
Selective logging—the practice of removing one or two trees and leaving the rest intact—is often considered a sustainable alternative to clear-cutting, in which a large swath of forest is cut down, leaving little behind except wood debris and a denuded landscape
