to know something backwards

• 完全了解； 了如指掌

to know something backwards的用法和样例：

例句

1. He is genned up about what to do and when to do.
   他已经完全了解该做什么，何时去做。
2. You know well about the accident.
   你完全了解这个事故。
3. She knows physiology from beginning to end.
   她对生理学这门学科了如指掌。
4. The designer is hip to the latest fashion.
   设计师对时装的最新款式了如指掌。