[名词解释] Willis环

TCBS平板中缺少的成分是() ["A．胆盐","B．蔗糖","C．亚硝酸盐","D．枸橼酸盐","E．硫代硫酸盐"] 猝倒发作 荚膜肿胀试验常用于鉴定() ["A．痢疾志贺菌","B．伤寒沙门菌","C．肺炎克雷伯菌","D．大肠埃希菌","E．产气肠杆菌"] 白喉棒状杆菌易形成异染颗粒的培养基是() ["A．血平板","B．沙保培养基","C．亚碲酸钾平板","D．吕氏血清斜面","E．克氏双糖培养基"] 出血动脉 Willis环