i'm supposed to be running和i am supposed to run的区别?

i'm supposed to be running和i am supposed to run的区别?
i'm supposed to be running和i am supposed to run的区别?

i'm supposed to be running和i am supposed to run的区别?
正在和一般的区别.
被期望在某时间正在做某事
被期望做某事
若没有特定的时间限制（如 at that moment \ second之类的）,常用后面那个吧.我觉得~