| Acknowledgements | 第1-6页 |
| Abstract | 第6-8页 |
| 摘要 | 第8-9页 |
| Contents | 第9-11页 |
| Chapter One Introduction | 第11-15页 |
| ·Background and Significance of the Study | 第11-13页 |
| ·Purpose of the Thesis | 第13页 |
| ·Organization of the Thesis | 第13-15页 |
| Chapter Two Literature Review | 第15-32页 |
| ·Key Terms in this Study | 第15-22页 |
| ·Complexity | 第15-17页 |
| ·Task and Task Types | 第17-22页 |
| ·Linguistic Complexity Measures | 第22-26页 |
| ·Measures of Lexical Complexity | 第22-24页 |
| ·Measures of Syntactic Complexity | 第24-26页 |
| ·Pervious Studies of Written Complexity at Home and Abroad | 第26-31页 |
| ·Previous Studies of Lexical Complexity | 第26-28页 |
| ·Previous Studies of Syntactic Complexity | 第28-31页 |
| ·Merits and Limitations of Previous Studies | 第31-32页 |
| Chapter Three Research Methodology | 第32-43页 |
| ·Research Questions | 第33-34页 |
| ·Participants | 第34-35页 |
| ·The Design of Writing Tasks | 第35-36页 |
| ·Research Procedures | 第36-37页 |
| ·Data Collection and Analysis | 第37-43页 |
| ·Selecting and Editing the Raw Samples | 第37-38页 |
| ·Marking the Selected Samples by Different Measure | 第38-40页 |
| ·Example of Marks and Calculation Steps | 第40-41页 |
| ·Collecting the above Calculated Data and Analysing by SPSS | 第41-43页 |
| Chapter Four Results and Data Analysis | 第43-65页 |
| ·Basic Descriptive Statistic of all Texts | 第43-44页 |
| ·The Influences of Task Types on Lexical Complexity | 第44-51页 |
| ·Lexical Variation | 第44-47页 |
| ·Lexical Density | 第47-51页 |
| ·The Influences of Task Types on Syntactical Complexity | 第51-61页 |
| ·Length of per T-units | 第51-54页 |
| ·Clauses per T-unit Ratio | 第54-58页 |
| ·Type of Subordination | 第58-61页 |
| ·The Summary of the Questionnaire Results | 第61-62页 |
| ·The Implications of the Results | 第62-65页 |
| ·The Theoretical Implications of the Results | 第62-63页 |
| ·The Pedagogical Implications of the Results | 第63-65页 |
| Chapter Five Conclusion | 第65-69页 |
| ·Main Finding of the Present Study | 第65-66页 |
| ·The Implications of the Present Study | 第66-67页 |
| ·Limitations and Recommendations for Future Researches | 第67-69页 |
| Bibliography | 第69-73页 |
| Appendix (A) | 第73-74页 |
| Appendix (B) | 第74-77页 |
| Appendix (C) | 第77-85页 |
| Appendix (D) | 第85-86页 |
| Appendix (E) | 第86-88页 |
