The girl was often heard __(to play/play)the piano in the next room.顺便问一下,被动的hear和look之类的动词,有often和主动语态一样加原型还是要加to之类的

问题描述:

The girl was often heard __(to play/play)the piano in the next room.
顺便问一下,被动的hear和look之类的动词,有often和主动语态一样加原型还是要加to之类的

加原型 play

to play 这要看其后跟的什么