The following metals: A. Aluminum B. Copper C. Zinc D. Titanium (fill in by serial number) ① The metal plated on the surface of white iron is _ _ _ _ _ _ _ _ _ _; (2) Silver-white packaging candy and cigarettes. ① The metal plated on the surface of white iron is zinc.

② The silvery white material for packaging candy and cigarettes is aluminum.

③ Titanium is widely used in aerospace industry and shipbuilding industry.

(4) Copper and aluminum are often used to make wires, because copper and aluminum have good electrical conductivity.