51. 輥輪標註“L30”其L表示
(A)左旋紋
(B)右旋紋
(C)粗紋
(D)細紋
答案:登入後查看
統計: A(2), B(0), C(0), D(0), E(0) #2900070
統計: A(2), B(0), C(0), D(0), E(0) #2900070