Archaeologists have been debating the origin of a rare form of lead found in Shang dynasty (1766–1046 BCE) bronze artifacts since its presence was discovered in China in the 1990s. Different researchers have proposed theories on which regions of the world would have had the raw materials containing the specific lead in these artifacts, but no conclusive evidence has been presented. What is intriguing is that bronze artifacts from China dated after the Shang dynasty do not contain this form of lead, suggesting that ______blank