Students of a vocational school in Lanzhou, Southwest China’s Gansu province show a globe-shaped Luban lock made by themselves on November 24, 2016. The traditional Chinese puzzle is formed by 12 precise metal parts. Lu Ban Lock is an educational toy invented by a famous ancient Chinese carpenter named Lu Ban. Each piece of the lock is interconnected without fixtures and players have to unlock the gadget and put the pieces back together. (Photo: China News Service/ Liu Yutao)
