cambium

例句：

1. 1.The cambium layer is where the tree's new growth starts.
   木层是树木新生长开始的地方。
2. 2. The cambium layer is also where the tree's nutrients are stored.
   木层也是树木养分储存的地方。
3. 3. The cambium layer is important for the tree's health and growth.
   木层对树木的健康和生长非常重要。