______is a rounded projection at the forward end of a ship which reduces water resistance,thus allowing an increase in speed when the ships is in ballast.
A. Bulbous bow
B. Ellipse bow
Cyclical projection
D. Gnomonic projection
首柱是首结构中的重要强力构件,其主要作用是:1.增强保留浮力; 2.便于甲板排水; 3.保持船体形状;
A. 1, 2, 4
B. 2, 3, 5
C. 3, 4, 5
D. 2, 3, 4