单项选择题
A.until
B.not until
C.not before
D.not after
单项选择题 Which of the statements listed concerning heat transfer is correct?（）
单项选择题 Which of the following operations must be entered on the Oil Record Book Part Ⅰ? （） Ⅰ.Routine discharge at sea of bilge water containing oil from the machinery spaces Ⅱ.Bunkering of fuel oil
单项选择题 The （）is used to measure power.