drop lineslot perpendicularnormal lineperpendicular linesplummet linev linesvertical line波面垂直线: orthogonal垂直线格式: format drop lines垂直线会聚: convergence of verticals垂直线偏振: perpendicular linear polarization垂直线圈法: perpendicular loop method; vertical-loop method下载手机词典可随时随地查词查翻译