girder iron

例句：

1. 1. The bridge's main girder is made of steel.
   这座桥的主要梁是用钢制成的。
2. 2. He used a steel girder to support the weight of the building.
   他用一根钢梁支撑着大楼的重量。
3. 3. The construction crew was using steel girders to reinforce the foundation.
   施工队正在使用钢梁加固地基。