Sometimes, backronyms come from outdated language. Writing "CC" at the end of a document once meant "carbon copy." ______________________Americans often use backronyms as jokes. For example, NASA, the U.S. space agency, named a treadmill on the International Space Station after the television personality Stephen Colbert. The agency created the name "Combined Operational Load-Bearing External Resistance Treadmill" to spell out the name COLBERT.有时候,反向缩略语来自于旧式语言.在文档末尾写上CC曾经意味的是复写副本.__________________________美国人经常利用反向缩略词来搞笑.例如,美国宇航局(简称为NASA)用电视名人斯蒂芬`科尔伯特(Stephen Colbert)来命名国际空间站上的跑步机.该机构创造了"Combined Operational Load-Bearing External Resistance Treadmill(组合式操作承重外部阻力跑步机)"这个名称来拼出COLBERT这个名字.