You can assign a variable to root of the current root tree. The variable is seen by all templates using the same root tree.

你可以在当前树形结构的‘根’中赋值一个变量。该变量可在所有使用该树形结构的模版中可见。

youdao

All reachable (and therefore live) objects in the VM can be found by tracing this tree (or trees) of object references called the GC root tree.

VM里所有能获得的对象能够通过跟踪被叫做垃圾回收根树的对象参考树来找到。

youdao

The copied tree is made a slave of the root tree so that mount actions in the root tree are propagated to the copy but not the other way around.

这个复制的树是根树的从属挂载，所以根树中的挂载活动会传播到这个拷贝，但是不会反向传播。

youdao

These include sassafras,vanilla, wintergreen, cherry-tree bark, licorice root, black cherry and cane sugar.

VOA: special.2011.08.01

The point I wanted to make is that for every node, except the leaves, the leaves are the bottom of a tree in this case, are weird, right, they draw trees where the root is at the top, and the leaves are at the bottom.

你没必要看到整棵树，我想说的重点是,对每个节点来说，除了叶子节点,叶子节点指的是树的最下面的节点，电脑科学家都很奇怪,他们画树的时候根是在最上面的。

麻省理工公开课 - 计算机科学及编程导论课程节选

Getting its name from the sassafras tree root originally responsible for its unique flavour, root beer was an exclusively North American beverage until recently.

BBC: What should I drink in your country?

One morning in September 1940, a boy called Marcel Ravidat was exploring the hills above Montignac when his dog, Robot, uncovered a hole beneath a tree root leading to a cave.

BBC: The perfect trip: Dordogne

The Pingwings were knitted penguin puppets who lived in Firmin's barn while The Pogles lived in a tree-root in a wood.

BBC: Oliver Postgate & Bagpuss