Undocumented
a. 无正式文件的, 无事实证明的
🗣️ 情景例句
Are you ready for this?
想听着。
He that has a tongue in his head may find his way anywhere.
遇事多问，随处可行。
Excuse me, Mr. Hu. Can you look after my watch, please?
劳驾，胡老师，你能帮我保管一下我的手表吗？