dragon bone短语¹⁰⁶¹⁰⁰⁺⁵ 基本例句 龙骨 The second and third chapter, also the main trunk parts, respectively probe into the characteristic and geographical distribution of dragon bone wheel and cylinder wheel. 第二、三章分别对龙骨车、筒车这两种典型灌溉农具的自身特点及空间应用拓展作进一步的探讨，是本文的主干内容。 fabiao