unprecedented词源

词缀un+词源preced+词缀ent+词缀ed，中文意思是adj. 前所未有的，史无前例的；（大小、数量、程度等）前所未知的，空前的

It was an unprecedented demonstration of people power by the citizens of Moscow.这是莫斯科市民对人民力量史无前例的证明。

The ceremony was disrupted by unprecedented heckling and slogan-chanting.