retromandibular vein

例句：

1. 1. The dentist removed the tooth and cleaned the root canal.
   牙医拔掉了这颗牙齿，清理了根管。
2. 2. The patient was given an injection to relieve the pain in his neck.
   病人被注射了以缓解颈部的疼痛。
3. 3.The surgeon performed a tracheotomy to treat the patient's breathing difficulties.
   外科医生进行了气管切开术，治疗病人的呼吸困难。