unprecedented

这项新技术有望实现效率的跨越式提升。

The new technology promises an ___unprecedented leap in efficiency.

互联网给予了人们前所未有的信息获取渠道。

The Internet has given people ___unprecedented access to information.

一次核事故可能造成前所未有的环境破坏。

A nuclear accident could cause ___unprecedented environmental damage.