单项选择题
A.1~4% B.0.1~0.4% C.10~40% D.0.3~8%
A.0.3%~0.8% B.3~8% C.30%~80% D.4~12%
A.凸形竖曲线、凹形竖曲线B.突起竖曲线、低洼竖曲线C.横形竖曲线、直形竖曲线D.倾斜竖曲线、水平竖曲线