An acronym is an abbreviation, a shorter version of a long word or expression. For example, the word "scuba" is an acronym. It stands for self-contained underwater breathing apparatus. But scuba is so much easier to say! Backronyms, on the other hand, are built in the opposite way. They are made by creating a phrase or expression for an already existing word or acronym. For example, the United States Department of Justice recently gave new meaning to its Amber Alert program. __________________________Acronym是指首字母缩略词,是一个长的单词或短语的缩写.例如,scuba这个单词就是首字母缩略词,它代表的是self-contained underwater breathing apparatus.但是scuba说起来就容易得多. 反向缩略语则以之相反.它们是为已经存在的单词或缩略语创造一条短语.例如,美国司法部最近赋予其安珀警报计划(Amber Alert program)新的意义._________________________