TOEFL Listening: ETS-TOEFL听力机经 - 334BAZ1C64_IL3RHP$

According to the professor, what is a vacuole? A. An enzyme commonly found in various protozoa B. A type of organ that is similar in design to a digestive tract C. A bubble of enzymes that is released to break down food particles D. A subunit within a cell that releases digestive enzymes