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'll have to ask a whole lot nicer than that I'm afraid.
恐怕你应该要问得有礼貌一点吧。
He has lived here for a year.
他在这儿住了一年。[持续到现在的行为]
Take a deep breath and I'll time you. But don't drown!
深吸一口气，我来给你计时。但别淹着！