Empty subtree
[计] 空子树
🧩 词语组成解析
empty
[ˈɛmptɪ]
adj. 空的，空虚的，空洞的;空闲的，无效的，徒劳的;无聊的，愚蠢的;言语或行动空洞的;
vt. （使）成为空的， 把…弄空;把…腾出来;
vi. 成为空的;流空;
n. 空车;空的东西;
subtree
[səbt'ri:]
子树;
🗣️ 情景例句
It's about my grandfather.
是关于我爷爷。
By doing nothing we learn to do ill.
懒散学为非。
They had a definite meaning, for they were as near as early man could get to writing.
它们有着一定的含义，因为它们已接近古代人的文字形式。