【正确答案】：
UNESCO（UNITED NATIONS EDUCATIONAL, SCIENTIFIC, AND CULTURAL ORGANIZATION）
【题目解析】：联合国：United Nations教科文分别指教育，科技和文化，也就是education，science，culture。这里修饰组织要用形容词形式，分别是educational,scientific, and cultural组织：organizationUnited Nations Educational, Scientific, and Cultural Organization是全称，也可以写首字母缩写UNESCO。UNESCO（United Nations Educational, Scientific, and Cultural Organization）属于文化习俗类用语。