Earth is a Glob of Molecules, many are Hydrogen and Oxygen, then Carbon makes us Carbon Based. When You see a Molecule Drawn on Paper or a White Board, Most of the Lines are Carbons, then it has other Things on it. H2O isn’t Carbon, O2 isn’t Carbon, but CO2 we exhale and Trees inhale. So most of the Lines in a Molecule Drawing are Carbons. In the Picture is Phenols Showing a Carbon Ring and the Carbon Lines.