单项选择题
A.reducing the erosion of the cargo tanks
B.increasing the total quantity of oil to carry
C.reducing the quantity of water contained in oil
D.reducing cargo discharged time
单项选择题 Where is the cooling water from the compensating tank in the cooling water system of main engine lead to?（）
单项选择题 From viewpoint of practice, it is sometimes important to detect abnormal happenings in the running gear by（）
单项选择题 If two fuel service tanks are installed, the empty tank should be pumped up directly it is emptyWhat is the meaning of “directly” in the sentence above?（）