||The total quality or weight of organsims in a given area or volume.
||The using up of a resource.
||The strength and vitality required fro sustained physical or mental activity
||a device that continuously changes the chemical energy of a fuel (as hydrogen) and an oxidant directly into electrical energy.
||Of, or relating to, or produced by the internal heat of the earth
||Of, or relating to, the nucleas of an atom.
||The prescence in or introduction into the environment of a substance or thing that has harmful or poisonous effects.
||The ability to do something or act in a particular way, esp. as a faculty or quality.
||Of, or relating to, or determined by the sun