digonal axistwo-fold axis二次: secondary; quadratic轴: axle; shaft复二次轴: didigonal axis次轴: secondary axis; secundary axis高次轴: axis of higher degree; axis of higher order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:二次轴，即可在微信中查询翻译
