One of them is Mark Combe, whose company is recycling industrial plastic waste.

马克·库姆就是这其中的一员，他的公司正在回收工业塑料废品。

So, we replace cement with something known as steel slag which is an industrial waste by-product of the steel making business.

因此，我们用钢渣代替水泥，钢渣是炼钢行业的工业废料副产品。