scrap iron

例句：

1. 1.The scrap iron was sold for recycling.
   这些废铁被用来回收。
2. 2. The factory uses scrap iron to make new products.
   这家工厂用废铁制造新产品。
3. 3.The scrap iron is collected from the streets and sold to metal recycling companies.
   废铁从街道上收集起来，卖给金属回收公司。