TOEFL Listening: TPO-TOEFL听力TPO - L220_0EUARH32FMHR$

What is the lecture mainly about? A. Explanations for a recent increase in the reindeer population B. Adaptatians that enable reindeer to live in cold climates C. Differences between newborn reindeer and adult reindeer D. Changes in the reindeer's food supply