A-team
noun /ˈeɪ tiːm/
  /ˈeɪ tiːm/
[usually singular]- the best sports team in a school, club, etc.(学校等的)最佳运动队,甲队 
- a group of the best workers, soldiers, etc.(工人、士兵等的)精英小组 
词源1970s: from sports terminology in which an organization's A-team is its best team.