He must be playing computer games at home,isn't he,为何用isn't

He must be playing computer games at home,isn't he,为何用isn't 关于He can't be at home,isn't he?此句是否为反义疑问句? Bob must be at home,________?A.mustn't he B.can't he C.isn't M_____ he isn't at home He must be ill ,for he isn't here. He isn't at school .I think he ( )be ill.can,shall,must,has he isn't in=he isn't at home吗? Mr.Wang isn't at home.He is at w() he isn't at school i think he -----be ill He is ( )home.He isn't( )school. He isn't at home.同义句转换 He isn't at home.写出同义句