A.MB=0 B.MA=3iθA C.QBA=0 D.QAB=-3iθA/l
A.QBA=-3iθA/l B.QBA=-6iθA/l C.QBA=-12iθA/l D.QBA=0
A.r11=r22 B.r12=r21 C.r12×Z2=r21×Z1 D.R1P=R2P