苹果青争
developing nations 发展中国家developed nations 发达国家 
发达国家 developed country 或developed nation发展中国家 developing country 或developing nation
developing country 发展中国家developed country 发达国家underdeveloped country 不发达国家
发达国家developped countries/nations 发展中国家developping countries/nations
the developed countries发达国家the development countries发展中国家
发达国家 developed countries发展中国家 developing countries
