被动语态要加上 tononononono这是一个难点啊，并不是有被动语态就要用不定式稍等在主动语态中,make , let , hear , see , watch , notice 等词,其后跟省略to的动词不定式(动词原形),在变为被动语态时,必须还原动词不定式符号to.如: We heard him sing this song in the room. He was heard to sing this song in the room. The boss made him work 14 hours a day. He was made to work 14 hours a day. I see him walk to school He is seen to walk to school.