open book 开放的书
read a book 读书
book club 读书会
1. Math has always been a closed book to me.
数学对我来说一直是难以理解的领域。
2. The new software is a closed book to most employees.
大多数员工对这款新软件完全不熟悉。
A: Can you fix this computer problem?
A：你能解决这个电脑问题吗？
B: Sorry, it's a closed book to me.
B：抱歉，这对我来说完全不懂。
1) 完全不懂的事情
2) 无法理解或掌握的内容
3) 对某人来说陌生或困难的事物
1. 对某人完全不熟悉的事物或领域
e.g. Physics was a closed book to her.
物理对她来说完全不懂。
noun phrase
1. Something that is completely unfamiliar or incomprehensible to someone.