38.水潤滑的艉軸不必設何裝置?
(A)艉密封裝置
(B)艏密封裝置
(C)阻隔環
(D)艏、艉密封裝置

答案:登入後查看
統計: A(41), B(16), C(10), D(4), E(0) #1188666