TOEFL Listening: ETS-TOEFL听力机经 - 9FFUG3Z_8_0GDAF6P$

What is main purpose of the lecture? A. To explain the cause of increasing temperatures in the far Northern Hemisphere B. To determine the reasons for the disappearance of two ancient societies C. To discuss how an ancient society survived by adapting to changing circumstances D. To examine one way that animal migration affected ancient societies