TOEFL Reading: ETS-TOEFL阅读机经 - 42Y_47I17564TOOJL$

According to paragraph 6, which of the following was true of at least some civilizations of the Bronze Age? A. They did not develop urban centers with large populations. B. They did not use metals to make bronze. C. They had an economy that was not based on agriculture. D. They did not use bronze for luxury items such as jewelry.