The first is made of glass and black iron.

VOA: special.2009.11.16

First of all, iron weapons, not bronze ones.

首先,铁制的兵器,而非青铜的

耶鲁公开课 - 古希腊历史简介课程节选

It was the first battle between iron ships.

VOA: special.2009.09.10

"We just labored really hard to say, okay,we're audience members who made the first 'Iron Man' successful and we're smart, which is kind of why we were drawn to it;

VOA: standard.2010.05.19