| Acknowledgements | 第1-5页 |
| ABSTRACT | 第5-7页 |
| 摘要 | 第7-10页 |
| List of Figures and Tables | 第10-11页 |
| Chapter 1 Introduction | 第11-14页 |
| ·A General Description of the Study | 第11-12页 |
| ·Purpose of the Study | 第12-13页 |
| ·Organization of the Thesis | 第13-14页 |
| Chapter 2 Literature Review | 第14-28页 |
| ·Cohesion Theory | 第14-23页 |
| ·A Brief Introduction to Cohesion | 第14-16页 |
| ·Texture and Structure, Coherence and Cohesion | 第16页 |
| ·Types of Cohesive Relations | 第16-23页 |
| ·Literature Review of the Study on Cohesion | 第23-24页 |
| ·The Researches on Cohesion Abroad | 第23-24页 |
| ·The Researches on Cohesion in China | 第24页 |
| ·A Brief Introduction to US Presidential Debates | 第24-27页 |
| ·Impromptu Speech | 第25-26页 |
| ·An Introduction to the US Presidential Debates | 第26-27页 |
| ·Conclusion of Cohesion Study | 第27-28页 |
| Chapter 3 Research Methodology | 第28-32页 |
| ·Data Source | 第28-29页 |
| ·Research Questions | 第29页 |
| ·Research Methodology | 第29-30页 |
| ·Quantitative Research | 第29-30页 |
| ·Qualitative Research | 第30页 |
| ·Research Procedure | 第30-32页 |
| Chapter 4 Analysis of Major Cohesive Devices in the Corpus | 第32-65页 |
| ·Reference Used in the US Presidential Debates | 第32-44页 |
| ·Personal Reference | 第32-37页 |
| ·Demonstrative Reference | 第37-40页 |
| ·Comparative Reference | 第40-43页 |
| ·Discussion of Reference in the US Presidential Debates | 第43-44页 |
| ·Substitution and Ellipsis Used in the US Presidential Debates | 第44-47页 |
| ·Conjunction Used in the US Presidential Debates | 第47-60页 |
| ·Additive Relation in the US Presidential Debates | 第47-51页 |
| ·Adversative Relation in the US Presidential Debates | 第51-53页 |
| ·Causal Relation in the US Presidential Debates | 第53-56页 |
| ·Temporal Relation in the US Presidential Debates | 第56-58页 |
| ·Discussion of Conjunction inthe US Presidential Debates | 第58-60页 |
| ·Lexical Cohesion Used in the US Presidential Debates | 第60-65页 |
| ·Reiteration Used in the US Presidential Debates | 第60-62页 |
| ·Collocation | 第62-63页 |
| ·The Discussion about Lexical Cohesion in the US Presidential Debates | 第63-65页 |
| Chapter 5 Conclusion | 第65-69页 |
| ·Major Findings | 第65-67页 |
| ·Significance of the Study | 第67页 |
| ·Limitations | 第67-68页 |
| ·Pedagogical Suggestions | 第68-69页 |
| References | 第69-73页 |
| Publication | 第73页 |
