This series has been widely used at home and abroad since its initial publication. Based on teachers impressions of, and suggestions for, the book over the past decade, the following changes have been made to the revised edition: restructured content and teaching procedures for a greater ease of use for both students and teachers; updated and relevant topics; increased exercises and class activities; two new books: including Testing Materials and Supplementary Reading Materials. The revised edition embodies a new process-oriented, task-based and interactive teaching method.