| Acknowledgements | 第5-6页 |
| Abstract | 第6-7页 |
| 摘要 | 第8-13页 |
| Abbreviations | 第13-14页 |
| Chapter One Introduction | 第14-18页 |
| 1.1 Background of the Research | 第14-16页 |
| 1.2 Objective and Significance of the Research | 第16-17页 |
| 1.3 Outline of the Thesis | 第17-18页 |
| Chapter Two Literature Review | 第18-42页 |
| 2.1 Hedging Study | 第18-35页 |
| 2.1.1 The Concept of Hedging and Hedges | 第18-22页 |
| 2.1.2 The Classifications of Hedging | 第22-26页 |
| 2.1.2.1 The Semantic Categories | 第22-23页 |
| 2.1.2.2 The Grammatical Categories | 第23-24页 |
| 2.1.2.3 The Pragmatic Categories | 第24-26页 |
| 2.1.3 Empirical Studies of Hedging in Academic Areas | 第26-35页 |
| 2.1.3.1 The Cross-linguistic or Cross-cultural Studies of Hedging in RAs | 第28-30页 |
| 2.1.3.2 The Cross-disciplinary Studies of Hedging in RAs | 第30-33页 |
| 2.1.3.3 The Studies of Hedging in RAs in China | 第33-35页 |
| 2.2 Conclusion Study | 第35-42页 |
| 2.2.1 Genre Analysis of RA Conclusions | 第35-36页 |
| 2.2.2 Previous Studies of Hedging in Conclusions | 第36-42页 |
| Chapter Three Theoretical Framework and Methodology | 第42-48页 |
| 3.1 Theoretical Framework | 第42-45页 |
| 3.1.1 Working Definition of Hedging in the Present Study | 第42页 |
| 3.1.2 Classifications of Hedging Adopted in the Present Study | 第42-45页 |
| 3.2 Methodology | 第45-48页 |
| 3.2.1 Sample Collection | 第45-46页 |
| 3.2.2 Research Steps | 第46-48页 |
| Chapter Four Research Results and Discussion | 第48-86页 |
| 4.1 The Overall Frequency of Hedging in MC and BC Corpora | 第48-50页 |
| 4.2 The Comparison of Hedging in Conclusions with Other Sections | 第50-52页 |
| 4.3 The Overall Frequency and Distribution of Different Hedging Types in BCand MC Corpora | 第52-54页 |
| 4.4 Categories of Hedges in the Two Corpora | 第54-84页 |
| 4.4.1 Lexical Hedges | 第54-78页 |
| 4.4.1.1 Modal Auxiliaries | 第55-61页 |
| 4.4.1.2 Full Verbs | 第61-66页 |
| 4.4.1.3 Adverbs | 第66-71页 |
| 4.4.1.4 Adjectives | 第71-75页 |
| 4.4.1.5 Nouns | 第75-78页 |
| 4.4.2 Non-lexical Hedges | 第78-84页 |
| 4.4.2.1 Clause Elements | 第79-81页 |
| 4.4.2.2 Questions | 第81-82页 |
| 4.4.2.3 Other Hedges | 第82-84页 |
| 4.5 Possible Interpretation for the Differences between the Two Corpora | 第84-86页 |
| Chapter Five Conclusion | 第86-90页 |
| 5.1 Major Findings | 第86-88页 |
| 5.2 Implications | 第88页 |
| 5.3 Limitations | 第88-89页 |
| 5.4 Suggestions for Future Study | 第89-90页 |
| References | 第90-97页 |
| Appendix A BC Corpus | 第97-100页 |
| Appendix B MC Corpus | 第100-103页 |
| Appendix List of Lexical Hedges Found in BC Corpus | 第103-105页 |
| Appendix List of Lexical Hedges Found in MC Corpus | 第105-106页 |
