States had at least three social levels, usually, an upper class of rulers, a middleclass comprised of managers and merchants, and a lower class of crop producers and agricultural laborers.
国家中至少有三种社会阶层，上层阶级（执政），中产阶级（商人，管理者）和下层阶级（农民，工人）。
2
It has consequences: South Africa's ongoing drought—the worst in three decades—will cost at least a quarter of its corn crop this year.
它的后果是：南非持续的干旱——三十年来最严重的干旱——将导致它今年至少四分之一的玉米作物受损。
3
Also, the tubers can be left underground for up to three years, so if drought kills a corn or bean crop, the farmer's family can still fend off starvation.