TOEFL Listening: ETS-TOEFL听力机经 - EKPM338ZAS34J83TP$

What is the main purpose of the lecture? A. A comparison between the functions of the alpha, beta, and subordinate members of animal groups B. An attempt to understand human effects on behavioral patterns of social animals C. An examination of the roles of a leader in an animal hierarchy D. A discussion about how human intrusion of animal habitats affects their internal roles