TOEFL Listening: TPO-TOEFL听力TPO - Q4UP7QLI33UZGB44R$

What does the professor mainly discuss? A. Comparisons between land animals and ocean-going animals of the Mesozoic era. B. Comparisons between sauropods and modern animals. C. Possible reasons why sauropods became extinct. D. New theories about the climate of the Mesozoic era.