| Acknowledgements | 第5-7页 |
| Abstract in Chinese | 第7-10页 |
| Abstract in English | 第10-13页 |
| Chapter 1 Introduction | 第19-24页 |
| 1.1 Research Background | 第19-21页 |
| 1.2 Research Purpose and Significance | 第21-22页 |
| 1.3 The Overall Organization of This Research | 第22-24页 |
| Chapter 2 Theoretical Framework | 第24-33页 |
| 2.1 Lexical Richness | 第24-27页 |
| 2.1.1 Concept of Lexical Richness | 第24页 |
| 2.1.2 Measurement of Lexical Richness | 第24-27页 |
| 2.2 Lexical Cohesion Devices | 第27-30页 |
| 2.2.1 Concept of Cohesion | 第27页 |
| 2.2.2 Concept of Lexical Cohesion | 第27-28页 |
| 2.2.3 Types of Lexical Cohesive Devices | 第28-30页 |
| 2.3 Formulaic Sequences | 第30-33页 |
| 2.3.1 Definition of Formulaic Sequences | 第30-31页 |
| 2.3.2 Identification of Formulaic Sequences | 第31-33页 |
| Chapter 3 Literature Review | 第33-42页 |
| 3.1 Research on Corpus Application in Writings | 第33-37页 |
| 3.1.1 Research on Corpus Application in Writings Abroad | 第34-35页 |
| 3.1.2 Research on Corpus Application in Writings at Home | 第35-37页 |
| 3.2 Research on Lexical Features in Writings | 第37-42页 |
| 3.2.1 Research on Lexical Richness in Writings | 第38-39页 |
| 3.2.2 Research on Lexical Cohesion Devices in Writings | 第39-40页 |
| 3.2.3 Research on Formulaic Sequences in Writings | 第40-42页 |
| Chapter 4 Research Methodology | 第42-52页 |
| 4.1 Objectives | 第42-43页 |
| 4.2 Research Questions | 第43页 |
| 4.3 Data Collection | 第43-49页 |
| 4.3.1 Scoring and Grouping of the Data | 第44-45页 |
| 4.3.2 Research Procedure | 第45-46页 |
| 4.3.3 Measurement Criteria | 第46-49页 |
| 4.4 Research Instruments | 第49-52页 |
| 4.4.1 RANGE | 第49-50页 |
| 4.4.2 AntConc | 第50-51页 |
| 4.4.3 SPSS | 第51-52页 |
| Chapter 5 Results and Discussions | 第52-78页 |
| 5.1 Results and Discussions of Lexical Richness and Word Frequency | 第55-66页 |
| 5.1.1 Results and Discussions of Lexical Richness | 第55-60页 |
| 5.1.2 Results and Discussions of Word Frequency | 第60-66页 |
| 5.2 Results and Discussions of Lexical Cohesive Devices | 第66-69页 |
| 5.2.1 The Distribution of Lexical Cohesive Devices | 第67-68页 |
| 5.2.2 Comparison of the Use of Lexical Cohesive Devices | 第68-69页 |
| 5.3 Results and Discussions of Formulaic Sequences Use | 第69-71页 |
| 5.3.1 The Frequency of Formulaic Sequences Used in Low Score Group | 第69-70页 |
| 5.3.2 The Frequency of Formulaic Sequences Used in High Score Group | 第70-71页 |
| 5.4 Results and Discussions of Pearson Correlation | 第71-78页 |
| 5.4.1 Pearson Correlation between Word Frequency and Writing Scores | 第71-74页 |
| 5.4.2 Pearson Correlation between Lexical Cohesive Devices and Writing Scores | 第74-76页 |
| 5.4.3 Pearson Correlation between Formulaic Sequences Use and Writing Scores | 第76-78页 |
| Chapter 6 Conclusions | 第78-83页 |
| 6.1 Major Findings | 第78-80页 |
| 6.2 Pedagogical Implications | 第80页 |
| 6.3 Limitation of the Research | 第80-81页 |
| 6.4 Suggestions for Further Research | 第81-83页 |
| Bibliography | 第83-88页 |
| Appendix | 第88-90页 |
| Papers Published During the Study for M. A. Degree | 第90页 |
