Tao Gong1, Lan Shuai2, Yicheng Wu3. 1. Center for Linguistics & Applied Linguistics, Guangdong University of Foreign Studies, Guangzhou, China; Educational Testing Service, Princeton, NJ, United States of America. Electronic address: tgong@ets.org. 2. Educational Testing Service, Princeton, NJ, United States of America. 3. Department of linguistics and translation, School of International Studies, Zhejiang University, Hangzhou, China. Electronic address: wuyicheng@zju.edu.cn.