unprecedented

形容词 unprecedented:

1. having no precedent; novel

1. Science and technology have come to pervade every aspect of our lives and, as a result, society is changing at a speed which is quite unprecedented.
   科学和技术已经开始渗透了我们生活的各个领域; 结果，社会正以空前的速度改变着。
2. We are seeing unemployment on an unprecedented scale.
   我们现在正经历规模空前的失业现象。
3. That is a situation unprecedented in the history of the school.
   这是该校有史以来未曾出现过的情况。
4. Some economists showed their anxiety on unprecedented level of unemployment.
   一些经济学家对失业率达到前所未有的程度表示忧虑。