如何表达对某事“了如指掌”？know sth like the back of one's hand

今日口语：

know sth like the back of one's hand

对某事了如指掌，非常熟悉

场景对话：

A: HeyEcho! Are you going anywhere on vacation this year?

二狗，你今年假期要去哪儿玩吗？

B: Yeah I’mgoing to Beijing with my parents.

我要带我爸妈去北京。

A: Well makesure you give my brother a call while you are in Beijing. He knows the citylike the back of his hand.

到了北京记得给我哥哥打电话啊，他对那里非常的了解。