TOEFL Listening: TPO-TOEFL听力TPO - 802R32T2B95T5W81R$

The professor describes the current method for producing cellulose ethanol. What are the two important steps she mentions? A. Yeast is added to cellulose to create an enzyme. B. An enzyme breaks down cellulose into sugars. C. Microorganisms ferment sugars into alcohol. D. Ethanol is extracted from certain microorganisms.