单项选择题
Bilge keels are fitted on ships to（）.
A.assist in drydock alignment B.improve the vessel's stability C.protect the vessel from slamming against piers D.reduce the rolling of the vessel
单项选择题 A wildcat is a（）.
单项选择题 A single fitting installed in a pipeline that either blanks off the pipe or allows a full flow passage of a liquid through the pipe is referred to as a（）.
单项选择题 A set of interior steps on a ship leading up to a deck from below is known as（）.
