本文仅代表作者本人观点，与本网立场无关。欢迎大家讨论学术问题，尊重他人，禁止人身攻击和发布一切违反国家现行法律法规的内容。 About the author: Zhang Xin（张欣） has been with China Daily since 1988, when he graduated from Beijing Foreign Studies University. Write him ...