We both came from Tsinghua University.  I graduated from Department of Precision Instruments and Mechanology in 1994 and Dong graduated from Department of Computer Science and Technology in 1993.  Five years (or over 20 years for Dong) of life in Tsinghua Campus left us innumerable great memories.  It is always a wonderful feeling to know that we share the same college experiences and life - classroom buildings we studied in, dining halls we ate at, gardens and parks we rambled in...