The New Encyclopædia Britannica

acid activity amount animals appears become blood body called carried cause cells century changes chemical close common complete consists containing continuous countries depends direction early effect evidence evolution example existence farm federal ferns fibres field Figure fire function gametophyte give groups important increase interest Italy kidney known later leaves less light lines living major marriage material means ment method move movements muscle natural normal obtained occur organs origin percent period person plants position possible present pressure problems produced properties protection reduced remain renal response result retina selection similar social species structure supply surface temperature tend tion types United urine usually various vary