简述离心泵的隔离？
参考答案：
①关闭泵入口阀及跨线阀
②关闭泵出口阀
③打开泵体排凝阀
④打开放空阀
疑为颅内动脉瘤破裂出血引起的蛛网膜下腔出血（SAH），选择哪段时间进行造影并发症最少（）。
A.5小时内效果最佳
B.1～3天内
C.3～7天
D.1～2周
E.2周以上
— What is your father?
— . [ ]
A. He's at home
B. He's a teacher.
C. She's a teacher
D. He's in his school
