The correct answer to this open question is the following.
Since the beginning of the Islamic era in 622, the diffusion of Muslim advancement in science, technology, or mathematics spread basically through trade and conquest. As Muslims conquered territories, they established trade routes and spread the Muslim's teachings to the conquered regions, although they allowed people to have their own belief systems.
So since medial times, Muslims shared their knowledge and inventions in the fields of astronomy, mathematics, algebra, cartography, geography, cosmology, alchemy, astronomy, opthalmology, chemistry, botany, agronomy, medicine, pharmacology, and the development of trade in the harsh conditions of the desert.
The Mongol Empire, with its peak size under the rule of Kublai Khan around the year of 1279, included parts of modern Russia in the North, modern day Korea, and modern China in the South on one end of the Asian continent. It stretched through the Asian continent all the way to modern day Hungary in Europe. It also included parts of the modern Middle East such as Iraq and Iran. The total area of the Mongol Empire in its peak was around 40 million km^2.
I would say the Jim Crow laws
Answer:
The social, economic and political conditions in Russia, before 1905 was quite backward. Social inequality was very prominent among the working class. Workers were divided on the basis of their occupation. ... Workers had strong links to the villages they came from and this also caused a social divide among workers
