What cultural relics were preserved during the Yanhuang period?

China's proven "history" is only 3600 years, that is, from the Shang Dynasty. The so-called "Xia Dynasty" has no definite evidence to prove its existence at present, and the world does not recognize the statement of the Xia Dynasty. The Erlitou site in Xia Dynasty unearthed a few years ago is no different from the tribes in the late Stone Age in scale, and this level of things does not prove the existence of Xia Dynasty. Although people hope that archaeological sites can dig up enough cultural relics as soon as possible to prove the existence of the Xia Dynasty, it is a pity that they have not yet. Even if the Xia Dynasty is included in the history, China has only 4,000 years of civilization. Don't add the period of the Yellow Emperor to "history" in order to fill the boastful vacancy of "five thousand years", because myths can't be included in history.