| Abstract | 第1-5页 |
| 摘要 | 第5-10页 |
| Tables and Figures | 第10-11页 |
| Abbreviations | 第11-12页 |
| 1. Introduction | 第12-16页 |
| ·Research background | 第12-13页 |
| ·Research questions and its significance | 第13-14页 |
| ·Organization of the thesis | 第14-16页 |
| 2. Literature Review | 第16-32页 |
| ·Language attrition | 第16-23页 |
| ·Definition of language attrition | 第16-17页 |
| ·Classification of language attrition | 第17-18页 |
| ·Variables affecting language attrition | 第18-23页 |
| ·Studies of language attrition abroad and at home | 第23-26页 |
| ·Studies abroad | 第23-25页 |
| ·Studies at home | 第25-26页 |
| ·Second language attrition theories | 第26-32页 |
| ·Retrieval Fail Hypothesis | 第26-27页 |
| ·Savings Paradigm Assumption and Relearning Hypothesis | 第27-28页 |
| ·Regression Hypothesis | 第28-29页 |
| ·Inverse Hypothesis | 第29页 |
| ·Critical Threshold | 第29-32页 |
| 3. Methodology | 第32-40页 |
| ·Research design | 第32页 |
| ·Research questions | 第32-33页 |
| ·Subjects | 第33-34页 |
| ·Instruments | 第34-36页 |
| ·Questionnaire | 第34-35页 |
| ·Language proficiency test paper | 第35-36页 |
| ·Procedures | 第36-37页 |
| ·Data collection | 第36-37页 |
| ·Data analysis | 第37页 |
| ·Methods once employed in attrition research | 第37-40页 |
| 4. Results and Discussion | 第40-54页 |
| ·Language attrition of English major Graduates | 第40-42页 |
| ·English proficiency in the pre-test | 第40-41页 |
| ·English proficiency test score in the post-test | 第41页 |
| ·Group differences between scores in the pre-test and post-test | 第41-42页 |
| ·Evidence of second language attrition of English major graduates | 第42页 |
| ·The impact of initial proficiency level on second language attrition | 第42-47页 |
| ·Subjects grouping | 第43-44页 |
| ·Proficiency level in the post-test | 第44页 |
| ·Second language attrition of the three groups | 第44-45页 |
| ·One-way ANOVA for the proficiency attrition of the three groups | 第45页 |
| ·The relationship between the initial proficiency level and attrition | 第45-46页 |
| ·Critical Threshold having effect on English attrition | 第46-47页 |
| ·Relationship between language attrition and exposure | 第47-52页 |
| ·Initial proficiency difference between the senior and junior groups | 第47-49页 |
| ·Difference in the second language attrition between the senior and junior groups | 第49-50页 |
| ·Association between the attrition degree and exposure to English | 第50-52页 |
| ·Summary | 第52-54页 |
| 5. Conclusion | 第54-58页 |
| ·Major findings | 第54-55页 |
| ·Limitations and suggestions for future study | 第55-56页 |
| ·Implications | 第56-58页 |
| Acknowledgements | 第58-60页 |
| Bibliography | 第60-66页 |
| Appendix | 第66页 |
