Which statement is TRUE concerning the gooseneck（）.

A.It is a sailing maneuver which brings the vessel's head through the wind

B.It connects the boom to the mast and allows the boom to swing freely

C.It is a sailing condition where there is a loss of air flow over the sails

D.None of the above

电容器两极板上总是带着等量的（），极板间的电压也高，所带的电荷就越多。