TOEFL Listening: ETS-TOEFL听力机经 - S9Z355K5IVD03V35P$

What point does the professor make when he discusses the formation of lunar soil? A. The formation process can be replicated using vacuum pyrolysis. B. The number of complex compounds in lunar soil is lower than scientists expected. C. Lunar soil is a product of repeated exposure to violent forces. D. Lunar soil is comprised primarily of iron compounds.