What does world war I and world war II have in common

World War I and World War II were wars conducted on a massive scale unlike any other wars in history. They were similarly caused by nationalism, imperialism, alliances, and militarism. Both wars saw countries trying to upset the power balance in Europe for their own gain.

Explanation: have a godd day

answer; i believe the two groups were irish immigrants and chinese immigrants;

the conditions that made the byzantine empire vulnerable to attacks by the muslin turks were the sack of constantinople by western crusaders, the conquests of the sultanate of rum, presence of rival kingdoms and finally the set up of fiefdoms at the empire which were owned by the ghazis (turkish warriors).