单项选择题
A.46.7 kN/m2 B.55.4 kN/m2 C.64.33 kN/m2 D.73.8 kN/m2
A.48.4 kN/m2 B.59.2 kN/m2 C.156.9 kN/m2 D.169.3 kN/m2