产褥感染中，最常见的病原菌是()致病性最强的病原菌是() ["A．溶血性链球菌","B．大肠杆菌","C．厌氧性链球菌及大肠杆菌","D．葡萄球菌","E．产气荚膜杆菌及肺炎球菌"]
致病性最强，可产生多种毒性物质，导致严重败血症()产生内毒素易发生菌血症而致感染性休克() ["A．大肠杆菌","B．厌氧性链球菌","C．葡萄球菌","D．溶血性链球菌","E．淋球菌"]
青年女性，乳腺超声发现边界光滑整齐，均匀的低回声() ["A．乳腺囊肿","B．乳腺叶状囊性肉瘤","C．乳腺纤维瘤","D．乳腺囊性增生","E．乳腺髓样癌"]
简述晚期产后出血的常见原因。
患者，女性，产后，右乳房肿胀，疼痛，红肿，超声见回声不均匀，低回声内见点状回声流动。如图所示考虑为() ["A．乳腺囊肿","B．乳腺脓肿","C．乳腺癌","D．乳腺腺瘤","E．纤维瘤"]
简述产褥感染的预防要点。
