It 's a range of the oldest Russian cities which were centers of the principalities during the ancient period of Russian history .
It 's a group of the oldest Russian cities which were centers of the principalities during the ancient period of Russian history .
It 's a group of the oldest Russian cities which were centers of the principalities during the ancient period of Russian history .
删除语法错误: It 's a range of the oldest Russian cities which were centers of the principalities during the ancient period of Russian history . 输出: