Father returned home. Mary was preparing dinner. Jane was lying in bed. (compound- complex sentence)
【正确答案】：When father returned home,Mary was preparing dinner and Jane was lying in bed.
【题目解析】：根据以上三个单句的关系，我们将其第一句处理为时间状语从句When，把第二句和第三句处理为主句。第二句和第三句我们用and来连接，表示当父亲回家时，玛丽在准备晚饭，简躺在床上。
