Undocumented
a. 无正式文件的, 无事实证明的
🗣️ 情景例句
This is a brand new product; it proved to be a craze in the American market.
这是一个全新的产品，在美国市场掀起了一股热销潮。
I told him to stay for supper.
我告诉他留下来吃晚餐。
He has a son and a daughter.
他有一个儿子和一个女儿。