“铜的”的英语？

它们有哑铜的，古铜的和镀银的。They are available in polished brass, antique brass or silver-plate.要求学生们检验铜的纯度.The students are asked to prove the purity of copper.夹头和电极之间的接触面是银的或铜的.The contact area between clamp and terminal is either ...