concrete key trench

例句：

1. 1. The construction crew was working diligently in the concrete key trench.
   施工队在混凝土槽道里勤奋地工作。
2. 2.The engineer used a concrete key trench to reinforce the foundation.
   工程师用混凝土槽道加固了地基。
3. 3. The construction project required excavating a concrete key trench for the pipeline.
   这个建筑项目需要挖掘一个用于管道的混凝土槽道。