upstream face

例句：

1. 1.The engineer carefully examined the upstream faceof the dam to ensure its stability.
   工程师仔细检查了大坝的上游面，以确保其稳定性。
2. 2. During theconstruction of the new bridge, the engineers focused onthe upstream face of the riverbed.
   在建造新桥的过程中，工程师们专注于河床的上游面。
3. 3. The upstream face of the mountain was covered insnow, making it difficult for climbersto reach the summit.
   山顶的上游面被雪覆盖，使得攀岩者难以到达顶峰。