rule
n. /ruːl/ A1
规则；规定
An official instruction saying what you must or must not do.
仙境例句
Nobody followed any rule at croquet, so everybody played at once.
打槌球时谁也不守规则，所以大家一起乱打。
原著这一句
“It’s the oldest rule in the book,” said the King.
“这是本子里最古老的规则。”国王反驳道。
卡罗尔原著 · 第 12 章