单项选择题
A.detract B.extract C.pump up D.pump down
（）, the repair in so short a time is unknown to us.A.Ho...
单项选择题（）, the repair in so short a time is unknown to us.
A.How they finished B.How did they finished C.That how they finished D.That how did they finished
Which of the following represents the maximum percent o...
单项选择题Which of the following represents the maximum percent of oxygen by volume required to be achieved by a ship’s inert gas system, prior to the commencement of crude oil tank washing?（）
A.6% B.8% C.10% D.12%
The fire of burning paper is classified as（）fire.A.Clas...
单项选择题The fire of burning paper is classified as（）fire.
A.Class A B.Class B C.Class C D.Class D
