being done与 done状语he slipped into the room,without himself being _英语解答

being done与 done状语
he slipped into the room,without himself being seen,为什么不用seen,而要用being seen ,

人气：186 ℃　时间：2019-10-11 07:55:36

解答

being seen表示被动语态.题目上说的意思是没有被看见.被动语态要用be动词加动词的过去分词形式.