一
1) 半个小时过去了，应该是过去式，所以go by 应该写为went by. 只好也表示当时的一种无奈的心情，可以用“不得不have to"表示。主干是：半个小时过去了，车没来，我们走回家。
Half an hour went by but the last bus has not arrived. we had to go home by walk.
2) 担心，用“worry”表示，“背熟”可以用“熟记于心”来表示。主干是：玛丽担心考试。
Mary looks have a worry about Chinese testBecause she has not learn the class article by heart.
3) “既然”可用"now that"表示。推迟用“postpone”表示。"已经推迟"说明了这件事情已经完成直到现在，因此用现在完成时表示。主干是：我们去参观博物馆。
Now that the basketball has been postponed，we can go to visit the museum.
4) “整个”用"all the way"表示，“在……期间”用"during" 表示。“住在”用“live in”表示。主干是：他和父母住在澳大利亚。
During the Second World War，his parents and he lived in Australia all the way.
5)“自……至今”可以理解为“从……到……”可以用"from to "表示，“失去联系”可以用“lose touch with”表示。主干是：我与我大学同学失去了联系。
From graduated Nanjing university to now， l lost touch with my college classments.
kind of 不知道应该加到什么地方。
二
“保持联系”用"keep in touch with " 朋友“friend”远方的朋友，用一个that引导的定语从句修饰friend.
Keep touch with friends that from distant places is not an easy thing.
"对我来说" 用"for me "，"情形"用“case”表示。
For me，this is the case.
“已经有几年了”用现在完成时表示，“have been”
Leave old neighborhood and friends that lived in neighborhood have been some years.
全文：
Keep touch with friends that from distant places is not an easy thing. For me，this is the case.
Leave old neighborhood and friends that lived in neighborhood have been some years.
