He Yong (L) helps a man ride his self-made wooden bicycle in the street on July 12, 2021 in Pingliang, Gansu Province of China. He Yong, 58, made the bicycle without nails, and all wooden components are connected by Sunmao, one of the oldest and most durable structures which were used in Chinese traditional architecture. (Photo by Zheng Bing/VCG via Getty Images)
