fedai

例句：

1. 1.The construction of the bridge required a large amount of iron.
   建造这座桥需要大量的铁。
2. 2. Steel is stronger and more durable than iron.
   钢比铁更坚固耐用。
3. 3.The steel industry plays an important role in the economy.
   钢铁工业在经济中扮演着重要角色。