black level restoration

例句：

1. 1. The team has beenworking on a project to restore the blacklevel of the river.
   该团队一直在努力修复河流的黑色水平。
2. 2. Theblack level restoration is crucialfor maintaining the ecological balance ofthe ecosystem.
   黑色水平恢复对于维护生态系统的生态平衡至关重要。
3. 3. Therestoration work was completed successfullyafter several months of effort.
   经过数月的努力，修复工作成功完成。