Valid function
[计] 有效函数, 有效操作
🧩 词语组成解析
🗣️ 情景例句
This dog is well trained.
这只狗受过很好的训练。
The bough that bears most, hangs lowest.
枝头结果越多，垂得越低。
The doctor began to operate on the boy.
医生开始给那个男孩动手术。