| Acknowledgements | 第1-4页 |
| Abstract | 第4-6页 |
| 中文摘要 | 第6-8页 |
| Table of Contents | 第8-10页 |
| List of Tables | 第10-11页 |
| List of Abbreviations | 第11-12页 |
| Chapter One Introduction | 第12-15页 |
| ·Background of the study | 第12-13页 |
| ·Need for the study | 第13页 |
| ·Significance of the study | 第13-14页 |
| ·The Structure of the thesis | 第14-15页 |
| Chapter Two Literature Review | 第15-28页 |
| ·Definition of lexical chunks | 第15-16页 |
| ·Classification of lexical chunks | 第16-19页 |
| ·In terms of structure | 第17-18页 |
| ·In terms of function | 第18-19页 |
| ·Theories related to this study | 第19-21页 |
| ·Dual-mode system of language learning | 第19-20页 |
| ·Information processing theory | 第20-21页 |
| ·Roles of lexical chunks in second language acquisition | 第21-24页 |
| ·Promoting language fluency and accuracy | 第21-22页 |
| ·Facilitating language production | 第22-23页 |
| ·Easing language processing | 第23页 |
| ·Increasing learners' motivation | 第23-24页 |
| ·Previous studies on lexical chunks | 第24-27页 |
| ·Studies of lexical chunks abroad | 第24-26页 |
| ·Studies of lexical chunks in China | 第26-27页 |
| ·Summary | 第27-28页 |
| Chapter Three Methodology | 第28-35页 |
| ·Research questions | 第28-29页 |
| ·Data collection | 第29-30页 |
| ·Oral part | 第29-30页 |
| ·Written part | 第30页 |
| ·Data preparation | 第30-31页 |
| ·Oral part | 第30页 |
| ·Written part | 第30-31页 |
| ·Data analyzing procedures | 第31-33页 |
| ·Identifying and categorizing lexical chunks | 第31-32页 |
| ·Counting word number and calculating frequency,distribution and variety of use of lexical chunks | 第32-33页 |
| ·Summary | 第33-35页 |
| Chapter Four Results and Discussion | 第35-47页 |
| ·General characte ristics of the learners' use of lexical chunks | 第35-39页 |
| ·Frequency,categories and distribution of use of lexical chunks | 第35-38页 |
| ·Variety of use of lexical chunks | 第38-39页 |
| ·Cross-level comparisons of the learners' use of lexical chunks in their oral and written narratives | 第39-43页 |
| ·Cross-level comparisons of the learners' use of lexical chunks in their oral narratives | 第40-41页 |
| ·Cross-level comparisons of the learners' use of lexical chunks in their written narratives | 第41-43页 |
| ·Relationship between the learners' use of lexical chunks and their oral and written performances | 第43-46页 |
| ·Relationship between the learners' use of lexical chunks and their oral performances | 第43-44页 |
| ·Relationship between the learners' use of lexical chunks and their written performance | 第44-46页 |
| ·Summary | 第46-47页 |
| Chapter Five Conclusion | 第47-51页 |
| ·Major findings of the study | 第47-48页 |
| ·Pedagogical implications | 第48-49页 |
| ·Limitations of the study | 第49页 |
| ·Suggestions for further research | 第49-51页 |
| References | 第51-53页 |
| Appendix Ⅰ TEM Band-4 writing rating criteria | 第53-54页 |
| Appendix Ⅱ Some selected samples for the study | 第54-64页 |
