A staff member shows the rare Ru guanyao brush washer from Northern Song Dynasty (960-1127) during Sotheby's Hong Kong's autumn sale for 2017, in south China's Hong Kong, Oct. 3, 2017. A new world auction record for Chinese Ceramics was set when a rare Ru guanyao brush washer from Northern Song Dynasty sold for 294.3 million HK dollars (about 37.7 mln U.S. dollars) after a 20 minute bidding battle at Sotheby's in Hong Kong here Tuesday. (Xinhua/Wang Shen)