解释下列加粗的词语。

(1)兵革非不坚利也_____   

     威天下不以兵革之利_____

(2)兵革非不坚利也_____   

     地利不如人和_____   

The device that allows a floating ship to sway without bending the marine riser system is the（）.

A.yaw joint

B.sway joint

C.slip joint

D.flex or ball joint