- Life Sciences
hollow tubular vascular tissue cells, strengthened with lignin that conducts water and mineral salts between roots, stems and leaves.
(also called elimination or defecation) the process whereby undigested food remains are expelled...
an international agreement to phase out the use of CFCs, signed by 49 countries in Montreal,...
rain that contains high levels of sulfuric acid, hydrochloric acid and nitric acid.
graphical representation of various aspects of food chains.