O 开头单词

once-forbidden adj.一次禁戒的

once-firing 一次烧成

once upon a time 从前

once upon a potty

once too often 又一次；次数太多

once through tubular boiler [交通运输工程]直流式锅炉

once through 单程的

once over

once more 再一次

once in a while

once in a way 偶尔

once in a lifetime love

once in a lifetime 一生一次

once in a blue moon 千载难逢；极为罕见

once for all 彻底地；一劳永逸地；只此一次

once every month 每月一次

once every four years 每四年一次

once caldas

once and for all change [经济学]一次性变动

once and for all