Did you know

1. Qutb al-Din al-Shirazi gave the first accurate explanation for the formation of a rainbow?

2. family registers are known as Koseki in Japan?

3. first head of the House of Saud was Muhammad bin Saud ?

4. Fataluku is a language commonly used on the eastern part of East Timor?

5. Guozijian was the national central institute of learning in Chinese dynasties after the Sui Dynasty?