United States of America美利坚合众国 United States Army美国军队 Universal Secure Access (Universal Secure Access Card Identifier)通用安全访问(通用安全准入卡标识符) United Software Association曼联的软件协会 Unusually Sensitive Area (environmental)异常敏感的区域(环境) Unix System AdminUnix系统管理员 Underground Service Alert地下服务警报 Unstable Angina不稳定心绞痛 Under Secretary of the Army在陆军大臣 United Stockgrowers of America曼联Stockgrowers美洲 United States Attorney美国的律师 Under Skirt Area在裙子 Union of South Africa南非联邦 University of South Australia南澳大学 United Space Alliance曼联的空间的联盟