One theory hinking many of the factors ( 3 ) in the emergence of these frst
arihzations Suggeste/人at the central organization required to manage irigationツin desert
areas so aowed omplex societiyto evohe as aree numbers ofpeople congregatedグto live
in the same
計 is tendency led eventually to the creation of the 信st cities and
2 Each of these threc early river-based civilizations developedのts own ways of