The light in the room must be turned off

The light in the room must be turned off It is cold in the room . You must have turned off the steam, he must be in the room ,because the light in the room is 麻烦He must be in the room,because the light in the room is___ she turned off the light and then_________ The light is on in his room ,I'm sure he ___back A.must be B the football must be()in the room 3.The light in the room------before you leave.A.are turned B It’s rather cold in the room.They ______ have turned off the 1.The light is ( ),He must be at home.A.off B.at C.in D.on He turned off the light to save electricity. Some turned off the light怎样改被动句