凸形竖曲线 convex curve: 凸曲线closed convex curve: 卵形线vertical curve: 竖曲线; 竖向曲; 竖直线; 纵断面曲线concave vertical curve: 凹形竖曲线crest vertical curve: 凸形竖曲线下载手机词典可随时随地查词查翻译