Which of the three biogeochemical cycles did not have a presence in the atmosphere?

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).

35 is your answer because i looked it up

it should be a. song dynasty’s civil service examination system created an administrative bureaucracy manned by the landed aristocracy.