关于肺韦格肉芽肿的描述，不正确的是() ["A．典型呈两侧大小不等的多发结节","B．约1/3～1/2的病人出现厚壁空洞","C．经治疗后空洞壁可变薄或完全消失","D．合并出血可呈大片实变阴影","E．多数病人有肺门及纵隔淋巴结肿大"]
中枢兴奋药按其主要作用部位和效应分哪几类?
上呼吸道与呼吸道的解剖分界是() ["A．口咽部","B．喉咽部","C．主支气管","D．环状软骨","E．甲状软骨"]
下列纵隔畸胎瘤CT表现，最具特征性的是() ["A．囊状低密度影","B．明显的钙化斑块","C．发现脂肪结构","D．出现脂肪－液体平面","E．增强边缘呈环状强化"]
何谓半数致死量和半数有效量?
何谓首关效应和后遗效应?
