Closed book
01
封闭的书, 谜
someone or something one knows very little or nothing about
Idiom
Informal
例子
The workings of the stock market are a closed book to me – I do n't understand how it works.
股票市场的运作对我来说是一本封闭的书——我不明白它是如何运作的。
The new technology is a closed book to most people – they're not familiar with it yet.
这项新技术对大多数人来说是一本封闭的书——他们还不熟悉它。
