做脑电图头皮电阻要求在______以下，最后______以下，如过高应______。
婴幼儿肺炎最常见的病理类型是() ["A．间质性肺炎","B．支气管肺炎","C．大叶性肺炎","D．毛细支气管炎","E．支气管间质性肺炎"]
女，13岁，发热、乏力数天，X线检查如图，最可能的诊断是() ["A．胸腺瘤","B．淋巴瘤","C．畸胎瘤","D．间皮囊肿","E．神经源性肿瘤"]
男，38岁，咳嗽、胸痛、咯血1天，X线检查如图，最可能的诊断是() ["A．炎性假瘤","B．原发性肺癌","C．肺结核球","D．肺转移瘤","E．结节病"]
男，61岁，痰中带血，X线检查如图，最可能的诊断是() ["A．结节病","B．右肺癌","C．右肺淋巴结肿大","D．肺转移瘤","E．炎性假瘤"]
诊断二度房室传导阻滞心电图最重要的依据是______。
