单项选择题
A.63,Ⅳ类围岩 B.63,Ⅲ类围岩 C.68,Ⅱ类围岩 D.70,Ⅱ类围岩
A.σ=0.08[σ] B.σ=0.78[σ] C.σ=0.83[σ] D.σ=1.11[σ]
A.130 d B.125 d C.115 d D.120 d