z三轴之矩为（）Amx(F)=ÖP，my(F)=–ÖP/，mz(F)=–ÖP/Bmx(F)=–ÖP，my(F)=ÖP/，mz(F)=ÖP/Cmx(F)=ÖP，my(F)=–ÖP/，mz(F)=Dmx(F)=–ÖP，my(F)=ÖP/，mz(F)=