单项选择题
A.a separator
B.oil
C.water
D.an oil collecting space
单项选择题 In a commonly used fuel oil system, the oil is stored in tanks in the double bottom from which it is pumped to （） and heated.
单项选择题 In a central cooling system, used in some modem ships, sea water is supplied to cool （）which will circulate to other individual cooler, greatly reducing the corrosion problems.
单项选择题 In a central cooling system, used in some modem ships, sea water is supplied to cool （）which will circulate to other individual cooler, greatly reducing the corrosion problems.