A.房间隔缺损 B.室间隔缺损 C.二尖瓣狭窄 D.二尖瓣关闭不全 E.主动脉瓣关闭不全
单项选择题30kW的X线机组,管电流的调节范围是()
A.10~80mA B.10~100mA C.10~400mA D.10~300mA E.10~200mA
单项选择题公众个人单个器官所受年剂量应低于()
A.5mSv B.10mSv C.25mSv D.50mSv E.100mSv