B.O. No4, Boundary Stone (IMAGE) The University of Hong Kong Caption This image shows (From left) HKU tutor Mr. Chan Yiu-hung, lecturer Dr. Stephen N.G. Davies, and tutor Mr. Choi Cho-hong discover B.O. No4. Credit The University of Hong Kong Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.