retroactive [ˌretroʊˈæktɪv]

例句:

• The seagulls swirled in aerial combat over the barges.
  海鸥盘旋在驳船上方，展开空中的搏斗。
  
• Even the seagulls are granite, grey and greasy.
  来自BBC
• a flock of seagulls
  一群海鸥
  
• Seagulls followed in the wake of the huge ship.
  海鸥尾随于大船之后.
  
• The seagulls plane and circle out of sight.
  来自J. Betjeman
• However, the limits would not be retroactive.
  来自VOA