A.5~8 B.8~10 C.10~15 D.15~18
A.构造深度、摩擦系数摆值 B.构造深度、摩擦系数 C.构造深度、摩擦力 D.粗糙度、摩擦系数摆值
A.87% B.90% C.93% D.95%