自发性蛛网膜下隙出血最常见的病因是()
A.动静脉畸形
B.血管炎
C.先天性动脉瘤
D.脑血管肌纤维发育不良
E.凝血系统异常
参考答案:C
I have two children, and _____ of them are working in the west of China. [ ]
A. all
B. both
C. neither
D. either
更换闸瓦时,严禁将手伸入()。