trunk demand circuit

例句：

1. 1. The trunk of the tree is where the roots grow.
   树的树干是根生长的地方。
2. 2. The trunk of the tree was badly damaged during the storm.
   暴风雨严重损坏了这棵树的树干。
3. 3. The trunk of the tree needs to be cut down for firewood.
   为了烧柴，这棵树的树干需要砍掉。