An Analysis of Public Service Announcements from the Perspective of At⁃titude in Appraisal System—Take TV PSA of Environmental Protection for Examples

With the development of social media,the TV public service advertisements play an important role in environmental pro⁃tection.The essay will analyze PSA about environmental protection from the perspective of Attitude in Appraisal System,trying to find out how ads work by using different kinds of sub-systems in attitude.And the essay will also focus on the proportion of positive and negative meanings,researching the myth of PSA.