骨牵引的禁忌证是（） ["牵引处有炎症","严重骨质疏松","老年患者","开放性骨折","不稳定性骨折"]
Shy―Drager综合征最典型的症状是（） ["共济失调","直立性低血压","眼球震颤","构音障碍","进行性肌强直"]
下列哪种手术不宜单独采用颈丛阻滞（） ["巨大甲状腺肿导致气管受压","甲状腺次全切除术","甲状腺囊肿摘除术","颈前部皮肤瘢痕切除术","颈淋巴结活检术"]
下列细菌的染色特性为异染颗粒的是（） ["麻风分枝杆菌","结核分枝杆菌","白喉棒状杆菌","破伤风梭菌","炭疽芽孢杆菌"]
阿片类药物拮抗剂是（） ["曲马多","双氢可待因","氧可酮","纳洛酮","美沙酮"]
管理经济学是研究什么的？它与微观经济学之间存在什么关系？
