What is the most amount of pollution recorded?

the difference is that white collar worker performs skills like worker as a scientist or well blue collars do physical work and they do services like being a cook.

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).