a closed book (to somebody)
成語所屬單字closed
a closed book (to somebody) — 慣用語
1. A topic or person that someone knows nothing about.
1.慣用語
釋義
一無所知的事物
A topic or person that someone knows nothing about.
例句
Advanced mathematics is a closed book to me.
To the new teacher, the school's history was a closed book.