tangent run-off切线: tangent缓和: relax; allay; calm; ease up; ...段: section; segment; part; para ...缓和段: transition zone超高缓和段: attainment of superelevation; superelevation runoff下载手机词典可随时随地查词查翻译关注微信公众号：chachacidian，回复:切线缓和段，即可在微信中查询翻译
