see sb doing sth 改成被动应该怎么改?
问题描述：
see sb doing sth 改成被动应该怎么改?
比如I see mary playing the voilin.
是Mary is seen to plying the voilin by me.
答
sb is/was seen doing sth
或者sb was/is seen to do sth
前者表动作,后者表状态