upstream floor

例句：

1. 1. The engineers were workingon the upstream floor of thedam.
   工程师们正在大坝的上游地面工作。
2. 2. The construction crew was installing theupstream floor of the new building.
   建筑工人正在安装新大楼的上游地面。
3. 3.The engineers were checking the upstreamfloor for any signs of leakage.
   工程师们正在检查上游地面是否有泄漏的迹象。