Some of the materials come from customers, some from scrap dealers.

有些材料来自客户，有些来自废品经销商。

Scrap dealers recover copper, aluminum, steel, glass, plastic and printed circuit boards.

废料经销商回收铜、铝、钢、玻璃、塑料和印刷电路板。

But scrap dealers don't destroy components that are still functional.

但废品经销商不会销毁仍在使用的部件。