People of Dong ethnic group prepare to take part in a contest of blowing reed-pipe wind instrument during a Ka Lau chorus festival in Bingmei township of Congjiang county, southwest China's Guizhou province, Nov 29, 2015. Ka Lau, the big song of the Dong ethnic group, has been inscribed in the UNESCO's intangible cultural heritage list since 2009. (Xinhua/Qin Gang)