单项选择题
A.a keen sense of hearing
B.rich theory
C.communicating ability with others
D.repetition work
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?（）
单项选择题 During tours of inspection in the machinery space, you found a fire on a running generator, what should you do first?（）
单项选择题 What is used for preventing pollution damage to the sea from ships?（）