TOEFL Listening: ETS-TOEFL听力机经 - PWC4V5293318AU1UP$

Why does the professor talk about making coffee? A. To describe how he dissolved coffee particles to prevent nucleation B. To introduce the concept of microwave superheating C. To reassure the students that some of the experiments will be as simple as making coffee D. To warn the students not to superheat liquids containing dissolved chemicals