1. I opened it and behind it was a wall of dirt shot through with the deep roots of trees.

2. Truffles are parasites that grow on the roots of trees.

3. The root of tree is waiting for your arrival.

4. The root of tree peony was long , so the container must be deep.

5. Concerning the familiar traversing through a program tree, people used to adopt the searching strategy, which always begins from the root of tree.