| ACKNOWLEDGEMENTS | 第5-6页 |
| 摘要 | 第6-7页 |
| ABSTRACT | 第7-8页 |
| Chapter One INTRODUCTION | 第13-17页 |
| 1.1 Background and Need for the Study | 第13-14页 |
| 1.2 Objectives and Significance of the Study | 第14-15页 |
| 1.3 Organization of the Thesis | 第15-17页 |
| Chapter Two LITERATURE REVIEW | 第17-35页 |
| 2.1 Key Concepts of DMs | 第17-22页 |
| 2.1.1 Definitions of DMs | 第17-18页 |
| 2.1.2 Classifications of DMs | 第18-21页 |
| 2.1.3 Functions of DMs in Written Discourse | 第21-22页 |
| 2.2 Concept of Expository Writing | 第22页 |
| 2.3 Theories of DMs | 第22-27页 |
| 2.3.1 Relevance-based Approaches to DMs | 第23-25页 |
| 2.3.2 Coherence-based Approaches to DMs | 第25-27页 |
| 2.4 Review of Related Studies | 第27-33页 |
| 2.4.1 Studies Related to the Use of DMs | 第27-30页 |
| 2.4.2 Studies Related to DMs Use in Different Types of Writing | 第30-32页 |
| 2.4.3 Studies Related to DMs Use in Expository Writing | 第32-33页 |
| 2.5 The Summary between This Study and the Researches above | 第33-35页 |
| Chapter Three METHODOLOGY | 第35-39页 |
| 3.1 Research Questions | 第35页 |
| 3.2 Research Participants | 第35-36页 |
| 3.3 Research Methods | 第36-37页 |
| 3.3.1 Writing Tasks | 第36页 |
| 3.3.2 Training on DMs Use | 第36-37页 |
| 3.3.3 Textual Analysis | 第37页 |
| 3.4 Research Instruments | 第37页 |
| 3.4.1 The Writing Samples | 第37页 |
| 3.4.2 Wang & Zhu’s Taxonomy of Discourse Markers | 第37页 |
| 3.5 Data Collection and Data Analysis | 第37-39页 |
| 3.5.1 Data Collection | 第37-38页 |
| 3.5.2 Data Analysis | 第38-39页 |
| Chapter Four RESULTS AND DISCUSSIONS | 第39-53页 |
| 4.1 Results and Discussions of the General Status of DMs Use in Four Writin Tasks | 第39-43页 |
| 4.1.1 The Categories of DMs Use in English Writing | 第39-41页 |
| 4.1.2 The General Status of the Frequency of DMs Use in Writing | 第41-43页 |
| 4.2 Results and Discussions of Development in the Use of DMs | 第43-53页 |
| 4.2.1 The Developmental Changes in the Frequency of DMs Use Over Time | 第43-45页 |
| 4.2.2 The Developmental Changes in the Category of DMs Use Over Time | 第45-47页 |
| 4.2.3 The Developmental Changes in the Location of DMs Use Over Time | 第47-49页 |
| 4.2.4 The Developmental Changes in the Accuracy of DMs Use Over Time | 第49-53页 |
| Chapter Five CONCLUSION | 第53-56页 |
| 5.1 Major Findings | 第53页 |
| 5.2 Pedagogical Implications | 第53-55页 |
| 5.3 Limitations and Suggestions for Future Study | 第55-56页 |
| REFERENCES | 第56-61页 |
| APPENDICES | 第61-65页 |
| Appendix Ⅰ Writing Tasks | 第61-62页 |
| Appendix Ⅱ Writing Samples | 第62-65页 |
