单项选择题
Ullages on tankers are measured from（）.
A.an above-deck datum such as the top of the ullage pipe B.the tank ceiling aboard transversely framed vessels C.the tank top D.a thievage mark below the edge of the deck
单项选择题 Ullages are measured from（）.
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（）.
