The Song Dynasty began in 960 and continued until 1279. In this era of substantial economic growth, China became the world’s strongest economy where science, technology, philosophy and mathe¬matics flourished. China back then was the first country in the world history to issue paper money. It is also in the Song Dynasty that gunpowder began to be used and movable-type printing was invented for the first time. With a booming population, more and more people migrated to cities where bustling places of entertainment could be found. There was a diversity of social activities. For example, citizens often gathered to appreciate and trade precious artworks. The governmental structure of the Song Dynasty was also advanced, with government officials all selected and appointed through competitive examinations.