an open book

基本解释

One of the misfortunes which always pursues the unbusinesslike is that, while they are as easy to read as an open book, they never learn to read the character of others.
不善經營的人常有這樣的一種不幸：他們自己像一本打開的書那樣，容別人看個仔細，但自己卻從不去學習怎樣看懂別人。
It's evolved since then into a social network: an open book on its members' lives, welcoming just about anyone.
後來它進化到一個社交網絡：一本關於它的成員的敞開的書，歡迎任何人來閲讀。
What we can also learn is that the web is an open book on people as it is on all companies.
另一點值得注意的是，互聯網不僅是一個關於人的開放課本，同時也是一本對於所有公司的開放課本。

But Adel, the thin young student, was there, sitting alone, an open book face down on his lap.
NEWYORKER: Waiting
What we can also learn is that the web is an open book on people as it is on all companies.
FORBES: What Can Julian Assange Learn from Steve Jobs' Spirit of Innovation?
Here too Mr Ebenstein's quandary becomes clear: Friedman was an open book, a fine expositor of his ideas and his life.
ECONOMIST: Milton Friedman