短语词组短语convex closed curve [数]凸闭曲线convex vertical curve 凸形竖曲线convex verticing curve 凸形竖曲线connected convex curve search 凸性连通分支搜索concave -convex curve 凸凹曲线strictly convex curve 严格凸平面曲线closed convex curve 卵形线 返回 convex curve