急性脓胸致病菌最多见的是
A．金黄色葡萄球菌
B．革兰阴性杆菌
C．溶血性链球菌
D．绿脓杆菌
参考答案：A
Even though he knew he would put his own life _____,he still felt _____ the new
treatment. [ ]
A. at a risk;like to try
B. at risks;like trying
C. at risk;like to try
D. at risk;like trying
一侧颈内动脉闭塞可以不出现临床症状，是由于（）
A.同侧颈外动脉未闭塞
B.对侧颈内动脉未闭塞
C.正常的脑底动脉环可迅速建立侧支循环
D.双侧椎动脉末端闭塞
E.颅内血管变异
