didn't leave his office-----he finished his homework ----填（）

He must have finished his homework,he A,mustn't B didn't Cha He didn't go to bed until he finished his homework.从句中的he可以省 "He didn't go to bed until he finished his homework "的同义句 句型转换 急He didn't go home until he finished his homework.(改为同义 @转换:He didn't go to bed until he finished his homework last he must have finished his homework last night,didn't he?为什么是 He didn't go to sleep ______he finished his homework.C. a 英语高高高 快进He didn't go to sleep______he finished his homework. He didn't do his homework yesterday. He won't leave his office ____he finishes his work he finished his homework _____. He___until he finished his homework?