I saw them play football in the park yesterday.改被动:They____ ____ _____play.
问题描述：
I saw them play football in the park yesterday.改被动:They____ ____ _____play.
答
they were seen playing football in the park yestrday by me.
答
They were seen to play football in the park yesterday.
答
They were seen to play football in the park by me yesterday
答
They had been seen play football in the park yesterday