an open book
US /ən ˈoʊpən bʊk/
UK /ən ˈəʊpən bʊk/
成语
一本打开的书, 坦率的人
a person or thing that is easy to understand or know about
示例:
•
She's always been an open book; you never have to guess what she's thinking.
她一直都是一本打开的书；你从不需要猜测她在想什么。
•
His past is an open book; there are no secrets.
他的过去是一本打开的书；没有秘密。