树干

例句：

1. 1. The tree's trunk is covered in green moss.
   这棵树的树干上覆盖着绿色的苔藓。
2. 2. The old tree hada very thick trunk.
   这棵老树有一个非常厚的树干。
3. 3. The tree'strunk was so strong that it could supportthe weight of the branches.
   这棵树的树干如此强壮，以至于可以支撑树枝的重量。