文字是人类进入文明时代的标志。
中原地区文明的起源是相当早的，在龙山时代晚期，中原地区已进入文明时代。
At the period of the later Longshan culture, the Central Plains area had entered civilization.
研究表明，中国古代北方草原游牧民族进入文明时代的时间较以前认定的时间提前了整整一代人。
It is verified that the time of ancient prairie nomad in North China coming into civilization is put forward to a whole generation before.
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