Traditional folk artists perform at a cultural festival in the ancient town of Qingcheng in Lanzhou, Gansu province, August 18, 2013. The 2013 Qingcheng folk art cultural festival is held during August 18-21, and every year it attracts many visitors from all over China. [Photo/CFP]

Traditional folk artists perform at a cultural festival in the ancient town of Qingcheng in Lanzhou, Gansu province, August 18, 2013. The 2013 Qingcheng folk art cultural festival is held during August 18-21, and every year it attracts many visitors from all over China. [Photo/CFP]

Traditional folk artists perform at a cultural festival in the ancient town of Qingcheng in Lanzhou, Gansu province, August 18, 2013. The 2013 Qingcheng folk art cultural festival is held during August 18-21, and every year it attracts many visitors from all over China. [Photo/CFP]

Traditional folk artists perform at a cultural festival in the ancient town of Qingcheng in Lanzhou, Gansu province, August 18, 2013. The 2013 Qingcheng folk art cultural festival is held during August 18-21, and every year it attracts many visitors from all over China. [Photo/CFP]