1.Up until now, people had to rely on post office boxes.
rely on信赖;依赖
He can rely on my support when the crunch comes.
关键时刻,他可以依靠我的支持 。
2.The 22 numbers from these coordinates are converted into three easy to remember words that replace house numbers, street and city names and zip codes.
convert into(使)转而变为…;折合
At what rate does the dollar convert into pounds?
美元以什么汇率兑换成英镑?
3.Poor addressing might seem no more than annoying in some countries.
no more than只是;至多
Their replies were no more than grunts of acknowledgement.
他们所谓的回答不过是表示承认的咕哝罢了 。