This undated file photo shows a cooking vessel unearthed at the Luojiahe cultural relic site in Chunhua County, Xianyang City, northwest China's Shaanxi Province. Multiple grain storage pits dating back more than 4,000 years were discovered in northwest China's Shaanxi Province, which offer fresh evidence for the study of early civilization in that area, according to archaeologists. (the Xianyang Cultural Heritage Institute/Handout via Xinhua)