Actors perform during a ceremony to mark the National Pavilion Day for the Islamic Republic of Mauritania at the 2010 World Expo in shanghai, east China, July 19, 2010. [Xinhua]

Actors perform folk music during a ceremony to mark the National Pavilion Day for the Islamic Republic of Mauritania at the 2010 World Expo in shanghai, east China, July 19, 2010. [Xinhua]