The oil bowl contains both water and oil, which appear as clearly separated substances only for a few days and as the show progresses we see that the water gets contaminated by the oil.
水和油同置于“油”碗里，并呈现出分明的两层。但是随着展出时间的变长，我们不难发现水被上层的油浸染。
2
Major causes for pollution from daily operation of oil depots are analyzed. Pollution source includes evaporation and leak of oils and discharge of contaminatedwater.