Undirected tree
[计] 不定向树
🧩 词语组成解析
a. 未受指导的, 无姓名和地址的
tree
[tri]
n. 树;木料;树状图;宗谱;
vt. 把…赶上树;使处于困境;把鞋型插入（鞋内）;
🗣️ 情景例句
One step at a time.
做事要一步一步来。
A guilty conscience is a self-accuser.
做贼心虚，良心自诛。
This is because they had no natural enemies until the arrival of humans and therefore did not need to develop flying wings.
这是因为人类到达这里之前，这些鸟没有天敌，因此，它们不需要发育飞行的翅膀。