单项选择题
The permant dunnage attached to the frames of the ship that aids in ventilation is (are) the（）.
A.hatch boards B.tank top C.hatch beams D.sweat bettens
单项选择题 The productivity of working shifts can be improved through a decrease of（）.
单项选择题 The purpose of cant frames in steel vessel is（）.
单项选择题 The ship is now too much listing to portaide. I suggest that you（）light cargo on portside and heavy cargo on starboard side.
