了如指掌

She knows physiology from beginning to end.

对这门科了如指掌。

She knows the layout of the back streets like the back of her hand.

对那些偏僻的街道了如指掌。

Tony is very hot on local history.

托尼对当地历史了如指掌。

She knows every nook and cranny of the city, so she’s the perfect guide.

对这个城市了如指掌，让做向道是再好不过了。