Undocumented
a. 无正式文件的, 无事实证明的
🗣️ 情景例句
Daddy, can we go soon?
爸爸 ，我们能快点走吗？
The wolf may lose his teeth, but never his nature.
江山易改，本性难易。
I can't believe a word you say.
我才不信你呢！