被动语态中要将省略的to还原的有哪些?
问题描述：
被动语态中要将省略的to还原的有哪些?
麻烦先分一下类,就是什么类型词的要还原to,再举几个常用的例子,
答
hear listen to watch see notice feel help
he was seen to enter the room.
She was heard to sing in the classroom.