1.句子主体：末班车还没来，但表转折，时间：半小时过去了，已经过去了用过去完成时。我们只好走回家，根据语境，用一般过去时
Half an hour had gone by,but the last bus hasn't come.So we had to walk home.
2.主干：玛丽担心汉语考试，原因是她还没背熟课文
Mary looks as if she is very warry about Chinese exam,because she hasn't learned the text by heart.
3.主干：我们去参观博物馆，条件篮球赛已被推迟，被动语态，现在完成时
Since the basketball match has been postponed,we might as well visit the museum.
4.主干：他一直住在澳大利亚，和他的父母，时间是整个二次世界大战期间。二战是过去的事，用一般过去时
All the way he stayed in Australia with his parents through the World War Ⅱ.
5.主干：我和我的大学同学失去了联系，过去完成时，时间自1985年从南京大学毕业至今，用since引导
I had kind of lost touch with my university classmates,since we graduated from Nan jing University in 1985.
