[img=,690,1427]https://ng1.17img.cn/bbsfiles/images/2019/01/201901171717330701_9462_3512623_3.jpg!w690x1427.jpg[/img][img=,690,920]https://ng1.17img.cn/bbsfiles/images/2019/01/201901171717333561_827_3512623_3.jpg!w690x920.jpg[/img][img=,690,920]https://ng1.17img.cn/bbsfiles/images/2019/01/201901171717337521_8869_3512623_3.jpg!w690x920.jpg[/img][img=,690,920]https://ng1.17img.cn/bbsfiles/images/2019/01/201901171717340271_3034_3512623_3.jpg!w690x920.jpg[/img][img=,690,517]https://ng1.17img.cn/bbsfiles/images/2019/01/201901171717344291_4532_3512623_3.jpg!w690x517.jpg[/img]
如图，这个小小的把粗的头和细的头连接起来的东西，学名叫什么？今天又拧断了一根