a material or substance that has no use or value that is made while producing something else 工业垃圾；（生产中的）无用副产品 Salts and other potentially harmful waste products are also generated. 还会产生盐和其他可能有害的废物。 In the end, they turned a waste product into something of value. 最后，他们将废品转化为有价值的东西。