a tree中文什么意思

• 树状
• 一棵树
• 一蔸树

• tree:    n. 1.树〔主要指乔木，也可指较大 ...
• in a tree:    在树上
• in the tree:    在树上（非树本身）

例句与用法

1. He crossed the river by the aid of a tree .
   他借助于一棵树过了河。
2. Her car ran off the road and hit a tree .
   她的车离开马路，撞在一棵树上。
3. A tree is a connected graph with no cycles .
   一个树是一个没有圈的连通图。
4. George washington had chopped down a tree .
   乔治华盛顿曾经砍倒了一棵树。
5. Stranded, he sat with his back to a tree .
   他束手无策，只好靠着一棵树坐下。