James Paul Gee put forward 5 discourse analysis approaches:Structure analysis, cognitive analysis, social and cultural analysis, critical analysis and comprehensive analysis. (James, 1999). This paper adopt M.A.K ’s Systemic Functional Linguistics as the applied approach to analyze the language materials especially focus on the cohesion of the language materials. (Halliday, 2001).
2.2 Corpus-based linguistics study  
  Generally, the literal meaning of corpus is a storage of language materials in the form of computer database,constructed to analysis the features of language using habits through the big data. It is a vital approach to conduct the language data collection and analysis in modern linguistic study. As a common approach to linguistics study,corpus can friendly present the overall statistical results including word frequency, word list, collocation results,sentence length which can relatively reflect the features of different literary forms thus making it valuable to the linguistic study. (O’Keeffe, 2003). NBA英语新闻语篇分析A Corpus-based Discourse Analysis of NBA News Report(2):http://www.youerw.com/yingyu/lunwen_21551.html