学校开除了数量空前的难以管教的小学生。Schools are booting out record numbers of unruly pupils.空前的成功纪录an unequalled record of success今年农民取得了空前的大丰收.The farmers got the biggest crop ever this year....

“空前的”的英语可以翻译为：all-time，record-breaking，[经] unprecedented，unheard-of，unparalleled ...