短語詞組短語parting ball structure 剝球構(gòu)造ball -like structure 球狀結(jié)構(gòu)ball face sealing structure 球面密封結(jié)構(gòu)parting -ball structure 剝球構(gòu)造ball and socket structure 關(guān)節(jié)構(gòu)造ball structure parting 球狀節(jié)理node ball of grid structure 網(wǎng)架節(jié)點球Twin ball -like structure 孿生球狀結(jié)構(gòu) 返回 ball structure