属于阴中之阳的是（） ["上午","下午","中午","前半夜","后半夜"]
属于阳中之阴的是（） ["上午","下午","中午","前半夜","后半夜"]
何谓医院内感染？有何特点？
患者有黄疸症状，伴有上腹绞痛、寒战、高热。最可能的病因诊断是（） ["病毒性肝炎","肝硬化","胆总管结石","原发性肝癌","壶腹部肿瘤"]
常以单纯机械性不完全性肠梗阻为表现的是（） ["嵌顿性股疝","肠蛔虫团堵塞","急性乙状结肠扭转","急性肠套叠","肠系膜上动脉栓塞"]
简述瓦斯爆炸和煤尘爆炸的区分。
