单项选择题
Ullages are measured from（）.
A.the tank ceiling B.the tank top bushing C.the thievage mark D.an above deck datum
单项选择题 Ullage measurements are taken from the top of the liquid to（）.
单项选择题 To serve as a person in charge of transfer operations on board a self-propelled tanker，an individual must（）.
单项选择题 To determine which grades of cargo a tanker is permitted to carry you should（）.
