对肝硬化门脉高压最有诊断意义的是（） ["下肢浮肿","食管胃底静脉曲张","胸水和腹水","脾大","肝大"]
对严重的支气管哮喘发作患者，重要的祛痰方法（） ["补液","体位引流","口服必嗽平","气雾吸入","吸痰"]
主要作用于β2肾上腺素能受体的支气管解痉药是（） ["异丙基肾上腺素","肾上腺素","氨茶碱","麻黄素","沙丁胺醇"]
胃溃疡最好发于（） ["胃底部","胃体部","胃窦小弯角切迹附近","胃窦近幽门前区","胃体底交界处"]
所谓内源性哮喘是（） ["哮喘持续状态","支气管哮喘与心源性哮喘同时并存","哮喘合并急性肺炎","感染性哮喘","同时对两种外源性过敏原产生反应"]
如何发现存在系统误差？
