单项选择题
（）on still water indictes how loading weight distribution affects on longitudinal strength.
A.Bending moment B.local strength C.shear force D.displacement
单项选择题 ANCHOR HAS ITS OWN CABLE TWISTED AROUND IT defines（）.
单项选择题 （）sends a radio signal from the bottom of the ship to the sea-bed,from which it is reflected.
单项选择题 The ARPA may swap targets when automatically tracking if two targets（）
