timbering to deep trenches

例句：

1. 1. Timbering is an essential part of the construction process.
   木材采伐是建筑过程的一个重要环节。
2. 2. The forestry department is responsible for timbering the area.
   林业部门负责该区域的砍伐工作。
3. 3.Timbering has a significant impact on the environment.
   砍伐对环境有重大影响。