Now countries which are great plains or which have as a chief means of transport some great river like the Euphrates or Nile tend to become united under some common rule.

• 现在，那些建立在大平原上的国家，或者以某一条大河，像幼发拉底河或者尼罗河，作为主要交通运输工具的国家，往往在某种统一管理下趋向团结。