fin girder

例句：

1. 1.The bridge is made of steel girders.
   这座桥是用钢桁架建造的。
2. 2.The engineer used the girder to support the load.
   工程师利用桁架来支撑负荷。
3. 3.The construction crew was working on the girder during the night.
   施工队在夜间正在桁架上工作。