trunk root union

例句：

1. 1. The trunk ofthe tree is growing stronger with each passingday.
   随着每一天的过去，这棵树的树干越来越强壮。
2. 2.The roots are intertwined, forming a strong union betweenthe tree and the soil.
   根相互交织在一起，形成了树和土壤之间的牢固联结。
3. 3.The union of the two species has ledto the creation of new hybrids.
   这两种物种的结合导致了新杂交品种的产生。