in and out
US /ɪn ənd aʊt/
UK /ɪn ənd aʊt/
成语
1.
进进出出, 来来回回
moving into and then out of a place, or repeatedly entering and leaving
示例:
•
The children were running in and out of the house all afternoon.
孩子们整个下午都在屋子里进进出出。
•
He's been in and out of the hospital for weeks.
他已经进出医院好几周了。
2.
了如指掌, 彻底
having a thorough knowledge of something
示例:
•
She knows the business in and out.
她对这行了如指掌。
•
You need to understand the system in and out to fix it.
你需要彻底了解这个系统才能修复它。