TOEFL Listening: TPO-TOEFL听力TPO - XO0JT4CKJYLHI9_6R$

What does the professor mainly discuss? A. Major changes in the migratory patterns of hummingbirds B. The adaptation of hummingbirds to urban environments C. Concern about the reduction of hummingbird habitat D. The impact of ecotourism on hummingbird populations