A.直立 B.俯斜 C.仰斜 D.背斜
A.h=1.33mE=89.76kN/m B.h=1.33mE=52.64kN/m C.h=1.33mE=80.64kN/m D.h=2.67mE=52.64kN/m
A.20°B.30°C.10°D.0°