单项选择题
A.M=7.5kN·m,V=21.02kN B.M=6.31kN·m,V=21.02kN C.M=6.31kN·m,V=18.31kN D.M=9.51kN·m,V=26.5kN
A.0.85 B.0.81 C.0.76 D.0.70