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 had some doubts about wanting to go to Michigan.
你对上Michigan大学有些疑虑。
Could you do me a favor?
能请你帮个忙吗？
I lent a pan to you two weeks ago. I've come to get it back again.
两个星期以前我借了一只锅给你。我来拿我的锅。