TOEFL Listening: ETS-TOEFL听力机经 - 4XI5RVRF4PK7MTO0P$

Why does the professor mention small holes found in the sides of some pools at one villa? A. To demonstrate the destructiveness of eighteenth-century treasure hunters B. To show how archaeologists determined that the villa was once used as a fish farm C. To explain how the pools were fed naturally by waters from the nearby sea D. To show a technique used by one emperor to make his estate more distinctive