I singing someone doing heard my honework while was I

I singing someone doing heard my honework while was I
I singing someone doing heard my honework while was I

I singing someone doing heard my honework while was I
I was doing my homework while I heard someone singing.

while I was doing my homework I heard someone singing

I was doing my homework while I heard someone singing. 当我听到有人唱歌时我正在写作业。进行时的用法啊