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.
不善经营的人常有这样的一种不幸：他们自己像一本打开的书那样，容别人看个仔细，但自己却从不去学习怎样看懂别人。
It's evolved since then into a social network: an open book on its members' lives, welcoming just about anyone.
后来它进化到一个社交网络：一本关于它的成员的敞开的书，欢迎任何人来阅读。
What we can also learn is that the web is an open book on people as it is on all companies.
另一点值得注意的是，互联网不仅是一个关于人的开放课本，同时也是一本对于所有公司的开放课本。

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