Tourist guides of Yangzhou Slender Lake Scenic Area balance books on their heads during an etiquette training class on May 18, 2017 in Yangzhou, Jiangsu Province of China. Tourist guides balance books on their heads with chopsticks in their mouths and poker in their hands under the guidance of a professional etiquette trainer. Tourist guides are trained to prepare for the upcoming China's National Tourism Day, which falls on May 19. (Photo by VCG/VCG via Getty Images)
