短语词组短语virtual steepness 虚陡度gradient steepness 梯度倾斜度slope steepness 边坡陡度;地形坡度steepness ratio 陡度比率characteristic steepness 特征波陡lightning steepness 雷电流陡度generalized steepness 广义陡度nominal steepness 标称陡度steepness method 陡度法 返回 steepness