In this file photo taken on Sept 18, 2011, Liu Yunshan (L, front), then a member of the Political Bureau of the Communist Party of China (CPC) Central Committee, also a member of the Secretariat of the CPC Central Committee and head of the Publicity Department of the CPC Central Committee, does water-saving experiment with elementary school students during a National Science Day campaign at the Moliyuan community of Chaoyang District of Beijing, capital of China. [Photo/Xinhua]