In this task, you are given a question and a context passage. You have to answer the question based on the given passage.
One example: what is the first event mentioned?, Context: The Russian Revolution is the series of revolutions in Russia in 1917, which destroyed the Tsarist autocracy and led to the creation of the Soviet Union. Following the abdication of Nicholas II of Russia, the Russian Provisional Government was established. In October 1917, a red faction revolution occurred in which the Red Guard, armed groups of workers and deserting soldiers directed by the Bolshevik Party, seized control of Saint Petersburg (then known as Petrograd) and began an immediate armed takeover of cities and villages throughout the former Russian Empire.
Solution is here: Russian Revolution
Explanation: This is a good example, and the Russian Revolution is the first event mentioned.

Now, solve this: Omaha tribes use what to determine social identity of mixed-race kids?, Context: The social identity of the children was strongly determined by the tribe's kinship system. Among the matrilineal tribes of the Southeast, the mixed-race children generally were accepted as and identified as Indian, as they gained their social status from their mother's clans and tribes, and often grew up with their mothers and their male relatives. By contrast, among the patrilineal Omaha, for example, the child of a white man and Omaha woman was considered "white"; such mixed-race children and their mothers would be protected, but the children could formally belong to the tribe as members only if adopted by a man.
Solution:
patrilineal