While I worked in the USA=( )( ) in the USA 中为什么前面while后用worked而不是working?

因为 work 是延续性动词,可以这么用,while = 在···期间；
如果用 working 则要在前面加 was ,或者将 I 去掉；
While I worked in the USA = During working in the USA = 在美国工作期间.可以这么说；如 study, stay, live, 等动词。