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Sanxingdui Site, 【小题1】 (date) back to 3,000 to 4,000 years ago, was first discovered in 1929. It is considered one of the most important archaeological sites along the upper reaches of the Yangtze River.

【小题2】 (get) a better understanding of the unique civilization, archaeologists reconducted an 【小题3】 (invest) of No. 1 and No. 2 pits in October 2019. This time, six more pits were discovered, including the largest gold mask ever found, ivory and silk.