钢是一种很硬的金属，人们用它来做刀、桥和大楼。

"钢" is a very hard metal that people use to make knives, bridges, and buildings.

钢比铁更硬、更结实，所以很多东西都是用钢做的。

"钢" is harder and stronger than iron, so many things are made of "钢".