首先 [词典] firstly; (最先) first; in the first place; first of all; above all; [例句]在任何时候任何情况下中国都不会首先使用核武器。At no time and in no circumstances will China be the first to use nuclear weapons.
Firstly,首先and then 其次,afterward 再次, finally 最后,造一个句子: Firstly I waked up late and then my breakfast was missing afterward the bus crashed finally I have been late.