Spacewalking astronauts inspected the joint several times before and even collected samples of the steel grit for analysis back on Earth. 太空行走的宇航员以前对接头曾进行过几次检查，甚至收集了钢屑样品回地球分析。
About half of our new steel is old steel,otherwise known as scrap. 我们大约有一半的新钢是旧钢，也叫作废钢。
However, the main material used in the EAF is scrap steel. 然而，在电弧炉法中主要的原料是废钢。
