Take the following as truth: The concentration of the metals, Al, As, Cr, Co, Cu, Fe, Pb, Ni, and Zn, expressed as total metal, should not exceed 1 eg/L each, and Cd, Hg, and Ag, expressed as total metal, should not exceed 100 ng/L each.
Then the following statement: "Al, As, Cr, Co, Cu, Fe, Pb, Ni and Zn are all metals." is true, false, or inconclusive?
Answer: True