Preorder traversal
[计] 前序遍历
🧩 词语组成解析
[计] 先根次序
[计] 遍历
🗣️ 情景例句
You are a terrific instructor, Jack.
你真是个了不起的教练 Jack。
Prosperity gains (or makes) friends, and adversity tries them.
顺境交朋友，逆境试真情。
I am sure that, without modern weapons,
我断定，如果没有现代化的武器，