改良Heller术的手术要点不包括（） ["切断食管下段一侧所有环行肌纤维","贲门部食管肌层切开长度不超过2cm","食管下段肌层切开长度至少应达8～10cm","常规做胃底折叠术以防胃一食管反流","术中应注意勿损伤胃一食管返折"]
腐败性脓胸是由哪种细菌引起的感染（） ["厌氧菌","大肠杆菌","真菌","绿脓杆菌","链球菌"]
食管癌起源于食管的（） ["黏膜层","黏膜下层","环行肌层","纵行肌层","浆肌层"]
三相负载不对称的低压供电系统中对中线有何要求？
肺癌最常见的肺部症状是（） ["呼吸困难","痰中带血","咳嗽","喘鸣","发热"]
斗式提升机的滚轮组的技术要求是什么？
