1.句子主干为我们走回家，时态为过去时，时间流逝用给出单词（go by），我们只好用（have to）。

Half an hour gone by，but the last bus hasn't arrived yet.We had to walk home.

2.句子主干为玛丽很担心，时态为现在完成时，背熟用给出短语（learn...by heart），后半句为前半句的原因，主人公为玛丽所以用第三人称。

Mary looked worried about the Chinese exam because she didn't learn the text by heart.

3.句子主干为我们去参观博物馆，球赛已经被推迟为现在完成时的被动，推迟用给出单词（postpone），前半句为后半句的原因可用since引出。

Since the basketball game has been postpone，we might as well visit the museum.

4.句子主干为他和父母住在澳大利亚，整个二战期间为过去时，一直用给出单词（all the way），住在澳大利亚为贯穿整个时期的事情所以用单词throughout。

He lived in Australia with his parents throughout the Second World War.

5.句子主干为我与大学同学失去了联系，自毕业至今是从过去一直延续到现在的动作用现在完成时，失去联系用给出单词（lose touch），前面可以用给出单词（kind of）意为“可以说”来修饰。

Since I graduated from NanJing University in 1985，I have kind of lost touch with my college students.

王璐瑶