短语词组短語micro -line-segment gear 微線段齒輪segment gear luffing 扇形齒輪變幅steering segment gear 轉曏扇形齒輪micro line segment gear 微線段齒輪a segment gear 扇形齒輪Micro segment Gear 微線段齒輪segment double circular arc gear 分堦式雙圓弧齒輪 返回 segment gear