单项选择题
Frames to which the tank top and bottom shell are fastened are called().
A.floors B.intercostals C.stringers D.tank top supports
单项选择题 Freeing ports on a vessel with soild bulwards().
单项选择题 Fuel oil tank vents are fitted with a screen which will stop().
单项选择题 Functions aboard a tanker or tank barge such as connecting, disconnecting, and topping off must be supervised by().