0 never having happened or existed in the past -- 史无前例的,空前的;绝无仅有的
This century has witnessed environmental destruction on an unprecedented scale. 环境在本世纪遭到了空前的破坏。
She took the unprecedented step of revealing the truth about the situation.
This did, however, bias the participants in an unprecedented, at times embarrassing, way.
Ecosystems are not being maintained, safety factors are ignored, species extinction persists at an unprecedented level, and our very global life-support systems are under threat.
As a result, vast financial resources were increasingly secured and redeployed to construct military and naval machines of unprecedented size, complexity, and cost.