concaver凹面体concaveadj.凹的n.凹面；凹线；凹形concave curvature凹曲度Concave deformity凹陷畸形concave clearance凹板间隙concave collector凹形接电器concave rim wheel槽缘轮concave landforms凹形地貌concave refractor上凹折射层concaved printing凹版印刷concave head bolt凹头螺栓concave-concaveadj.双凹的；两面凹的