Water started leaking from a tank yesterday at 12:00 noon at a constant rate of 0.5 ounce per second and continued leaking at this rate until the tank was empty. If the tank was empty before 8:00 yesterday evening, which of the following could have been the amount of water in the tank, in ounces, yesterday at 12:00 noon?
Indicate all such amounts.
答案：A,B,C,D