TOEFL Listening: TPO-TOEFL听力TPO - I23OU0S0X9UP563PR$

What is the lecture mainly about? A. New information about glass production and use in ancient Egypt. B. Whether Egyptians or Mesopotamians were the first to invent glass. C. Differences between Egyptian glass and other kinds of glass. D. Reasons why ancient Egyptians imported glass from other countries.