男。60岁,因咳嗽,活动后气短,发现胸腔积液,胸水化验为渗出液,经抗结核治疗两个月,胸水不减少反而增多,为明确诊断,进一步应采取的措施是() ["加强抗结核治疗","胸水的酶学检查","胸水的结核杆菌培养","胸部B超检查","胸水的病理细胞检查和胸膜活检"]
预示着HBV复制减少或终止,传染性减弱的抗体是() ["抗-HBe","HBcAg","抗-HBc","HBeAg","抗-HB"]
用离子选择电极法测定空气中氟含量时,加入离子强度调节剂的作用有() ["保持一定的酸度","控制离子活度基本恒定","排除干扰","防止产生迁移电流","提高回收率"]
外周阻力和心率不变而搏出量增大时,动脉血压的变化主要是() ["收缩压升高","舒张压升高","收缩压和舒张压等量升高","收缩压升高,舒张压降低","收缩压降低"]
喉返神经麻痹者() ["咳嗽声音低微或无声","咳嗽声音嘶哑","金属音调咳嗽","阵发性连续剧咳伴有高调吸气回声(鸡鸣样咳嗽)","咳嗽、咳粉红色泡沫痰伴呼吸困难"]
什么是直流放大器?有哪几种?