TOEFL Listening: ETS-TOEFL听力机经 - ACI528MKN9UCA77FP$

What's the professor's main point about Titan? A. Titan's atmosphere is causing its surface conditions to slowly change. B. The chemical processes that occur on Titan are unique in the history of the solar system. C. Research on the atmospheric conditions on Titan may help explain how it came into existence. D. Studying Titan can help provide a better understanding of conditions on early Earth.