过去进行时例句（主动语态）。
I was doing my homework when you came back last night.
改成被动语态。
My homework was being done by me when you came back last night.
例句
I was eating dinner when you called me.
Dinner was being eaten by me when you called me.
被动语态动词格式: 根据被动语态的主语，选择was 或者were，being是必须的，再加上行为动词的过去分词。
过去进行时的主动语态是was/were doing，被动语态was/were beingdone. was用于主语是(我，它他她以及单数名词）were用于主语是（你 你们 我们 他们及复数名词）
英语的被动语态的基本结构是 be +pp而be的过去进行时是 was/were being，所以过去进行时的被动语态就是 was/were being done
例句 Our fur was being used to make sweaters for the people like you .
