汽车起动系主要由()组成。 ["A、起动机","B、发电机","C、发动机","D、蓄电池","E、点火开关"]
牙体预备时,为减小对牙髓的损害所采取的措施是() ["水雾冷却","间歇切割","短时切割","轻压磨切","以上都对"]
关于HAP,叙述正确的有() ["包括在医院内获得感染而于出院后48h内发病的肺炎","VAP是最常见的HAP","需入住ICU的HAP可诊断重症HAP","重症HAP的最初经验性治疗应覆盖铜绿假单胞菌、不动杆菌和MRSA等高耐药菌","对晚发性HAP和VAP,不论其是否达到重症诊断标准,抗感染治疗均按重症处理"]
一般情况下余留牙的拔除牙槽骨吸收应达到() ["牙根1/4","牙根1/3","牙根1/2","牙根2/3","以上均不对"]
12位(bit)的成像系统能提供的灰度级数为(). ["256","512","1024","2048","4096"]
发电厂接于220kV双母线上有三台及以上变压器,则应有至少每条母线有()变压器中性点直接接地。