Country is the most usual word to use when you are talking about the major political units that the world is divided into. State is used when you are talking about politics or government institutions. ...the new German state created by the unification process. ...Italy's state-controlled telecommunications company. State can also refer to a political unit within a particular country. ...the American state of California. Nation is often used when you are talking about a country's inhabitants, and their cultural or ethnic background. Wales is a proud nation with its own traditions... A senior government spokesman will address the nation. Land is a less precise and more literary word, which you can use, for example, to talk about the feelings you have for a particular country. She was fascinated to learn about this strange land at the edge of Europe.

当谈论世界所划分成的主要政治单位时， country 最为常用，当谈论政治或政府组织时用 state。例如，the new German state created by the unification process (统一后成立的新德国)，Italy's state-controlled telecommunications (意大利由国家控制的电信公司)。state 还可指某国国内的行政单位，例如，the American state of California (美国加利福尼亚州)。当谈论某国的居民及其文化或种族背景时常用 nation。例如：Wales is a proud nation with its own traditions (威尔士是一个拥有自己传统的自豪的民族)，A senior government spokesman will address the nation (一位政府高级发言人将发表全国讲话)。land 含义较为笼统而文学意味更浓，可用来谈论对某国的感情等。例如，She was fascinated to learn about this strange land at the edge of Europe (她非常渴望了解这个位于欧洲边缘的奇异国度)。