TOEFL Listening: ETS-TOEFL听力机经 - 65Z541IF3I6657QQP$

What does the professor mainly discuss? A. Why extinction rates among insect species are lower than those for other animals B. How two insect species have survived through a mutualistic relationship C. Interrelated factors involved in the conservation of a particular insect species D. Evolutionary effects brought on by changes in the diet of an insect species