TOEFL Listening: ETS-TOEFL听力机经 - PDTJ2YQOU0EYB4XRP$

According to the professor, what was one way in which hunter-gatherers benefited after the glaciers retreated? A. The warmer climate allowed them to build simpler, lighter houses B. The appearance of open grasslands provided easier access to food C. An increase in the number of lakes attracted more migrating animals D. An increase in annual rainfall made farming more productive