进行SF6气体取样,取样完毕卸下取样瓶连接头前,应检查取样瓶()是否已关闭严密。
A.真空泵阀门
B.取样器排空阀门
C.取样瓶阀门
D.设备阀门
参考答案:C
关于强心苷,哪项错误()
A.有正性肌力作用
B.有正性心肌传导功能
C.有负性频率作用
D.安全范围小
E.用于治疗心衰,也可治疗室上性心动过速
Student loan is supposed to provide financial support for people who would _____ not be able to go to college. [ ]
A. therefore
B. meanwhile
C. otherwise
D. nevertheless