Query: How many items does the Nanjing Museum contain?
Context: Nanjing has some of the oldest and finest museums in China. Nanjing Museum, formerly known as National Central Museum during ROC period, is the first modern museum and remains as one of the leading museums in China having 400,000 items in its permanent collection,. The museum is notable for enormous collections of Ming and Qing imperial porcelain, which is among the largest in the world.