Fill in the appropriate unit name in the horizontal line. The height of the flagpole is 15 _ _ _ _ _ A classroom covers an area of about 80 _ _ _ _ _ The volume of the fuel tank is16 _ _ _ the volume of a math book. The flagpole is 15 meters high, and a classroom covers an area of about 80 square meters. The volume of the oil tank is 16 liter. The volume of a math book is about 200 square centimeters. The volume of a refrigerator is about 220 liters, and the volume of a potato is about 800 cubic centimeters. So the answer is: meter, square meter, liter, square centimeter, liter, cubic centimeter.