我们经常会说：中国的历史有“上下五千年”。那是从“三皇五帝“开始算起的。We often say that the history of China is " From BC to AD, there are five thousand years of time.". That's from the Three Kings and Five Emperors. 真正有准确年代记载的，是从公元前2146年的“夏朝”开始，到1911年“清朝”结束，大致经历了18个皇朝。The real accurate chronological records, from the "Xia Dynasty" in 2146 BC to the end of the "Qing Dynasty" in 1911, roughly experienced 18 imperial dynasties.