| Abstract | 第1-6页 |
| 摘要 | 第6-10页 |
| Chapter One Introduction | 第10-14页 |
| ·Research Background of the Study | 第10-12页 |
| ·Purpose and Significance of the Study | 第12页 |
| ·Research Questions | 第12-13页 |
| ·Organization of the Thesis | 第13-14页 |
| Chapter Two Literature Review | 第14-26页 |
| ·A Brief Introduction of the Research History of Lexical Chunks | 第14-15页 |
| ·Definition of Lexical Chunks | 第15-16页 |
| ·Classification of Lexical Chunks | 第16-20页 |
| ·Main Views of the Theory of Lexical Chunks | 第20-22页 |
| ·Composition of Language | 第20页 |
| ·Grammaticalized Lexis of Language | 第20-21页 |
| ·Creativity and Productivity of Language | 第21页 |
| ·Fluency Devices of Language | 第21页 |
| ·Acquisition of Language | 第21-22页 |
| ·Advantages of Lexical Chunk Approach to the Teaching of Business English Writing | 第22-23页 |
| ·Facilitating Memorization of Vocabulary | 第22-23页 |
| ·Avoiding Inappropriate Use in Terms of Register | 第23页 |
| ·Enhancing Written Fluency | 第23页 |
| ·Characteristics of Lexical Chunks in Written Discourse —Business Letter | 第23-26页 |
| Chapter Three Research Methodology | 第26-28页 |
| ·Participants | 第26页 |
| ·Materials | 第26-27页 |
| ·Data Collection | 第27-28页 |
| Chapter Four Research Findings and Discussion | 第28-38页 |
| ·General Characteristics of the Use of Lexical Chunks in Business English Writing | 第28-30页 |
| ·General Condition of the Use of Lexical Chunks | 第28-29页 |
| ·Frequency of the Use of Lexical Chunks | 第29-30页 |
| ·Diversity of the Use of Lexical Chunks | 第30页 |
| ·Comparison between High-rated and Low-rated Business English Writings | 第30-34页 |
| ·Comparison of the Use of Polywords | 第31-32页 |
| ·Comparison of the Use of Institutionalized Expressions | 第32页 |
| ·Comparison of the Use of Phrasal Constraints | 第32-33页 |
| ·Comparison of the Use of Sentence Builders | 第33-34页 |
| ·The Relationship between Learners’Use of Lexical Chunks and the Improvement Of Their Business English Writing Ability | 第34-38页 |
| Chapter Five Conclusion | 第38-43页 |
| ·Summary of the Research Findings | 第38-40页 |
| ·Pedagogical Implications | 第40-42页 |
| ·Teaching Vocabulary on the Basis of Lexical Chunks | 第40页 |
| ·Organizing Discourse by Lexical Chunks | 第40-41页 |
| ·Designing Lexical Chunk-based Exercises | 第41-42页 |
| ·Limitations of the Present Study and Suggestions for Further Research | 第42-43页 |
| Bibliography | 第43-48页 |
| Appendix I Two Writing Samples of the Participants | 第48-50页 |
| Appendix II BEC-higher Writing Test Assessment Sheet | 第50-52页 |
| Appendix III Results of T-test with SPSS 13.0 | 第52-54页 |
| Acknowledgements | 第54页 |
