ferrum

例句：

1. 1. The ancient Romans used to make their weapons with ferrum.
   古罗马人过去常用铁制造武器。
2. 2. The steel industry is a major contributor to the economy of our country.
   钢铁工业是我国经济的主要贡献者。
3. 3. The hammer was made from ferrum and had a sharp edge.
   锤子是用铁制成的，边缘很锋利。