1.A half of an hour was going by，but the last bus also was not arrived，so we can just walk to home.
主干:我们走回家 与前面是因果关系所以用so连接，半个小时过去了但车还没来，用过去式，我们走回家用一般现在时，“只好”用just
2.Mary seemed to be warried about the chinese exam,because she is not learning passage by heart.
主干:玛丽担心考试 后面句子是解释她担心的原因用because连接，“看起来担心”是用过去式，“她还没有背熟课文”是现在的状态，用一般现在时
3.Since the basketball competition was postponed,we can visit the museum to instead.
主干:我们去参观博物馆 前面句子是解释去博物馆的原因，“既然”用since，已经知道篮球赛被取消，所以用被动，过去式，因为篮球赛取消而去参观博物馆，用instead
4.All the way at the world war ‖,he lived in the Australia with his parents of all time.
主干:他住在澳大利亚 前面句子说明这件事发生的时间，是用过去式，一直用of all time
5.Since I graduated from NanJing universty in1985 to now, I have kind of lose touch with my classmates.
主干:我和同学失去联系 前面句子解释了时间是从毕业到现在，所以“毕业”用过去式，“自从”用since，年份前加in，“失去联系”是现在的状态，用一般现在时
