she __ (study) art in a school when i began to work in the factory.was studying

问题描述:

she __ (study) art in a school when i began to work in the factory.was studying
为何不可用had studied?

这里的意思是:当我开始工作时她正在学艺术,主要强调的是某个时候某个人正在做的事
我开始工作是一个短暂的时间,不能用完成时.完成时后接一段时间