蛛网膜下腔出血最常见的病因是( )
A．脑血管畸形 B．脑动脉炎 C．脑动脉粥样硬化D．再生障碍性贫血 E．先天性动脉瘤
参考答案：E
— Could I speak to Mr. Brown?
— ____ I'll go and see if he is in. [ ]
A. Who are you?
B. He isn't here.
C. I'm sorry.
D. Hold on, please.
General communications are those communications（）.
A.between ship stations and shore-based communication networks
B.concern the management and operation of ships
C.may have an impact of the safety on ships
D.all of A, B, C
