食管裂孔疝的间接X线征象有（）
A.食管返流
B.食管胃环
C.食管胃角变钝
D.食管下段迂曲增宽
E.消化性食管炎
参考答案：A, C, D, E
________ the civil service has its obvious advantages，it doesn’t necessarily suit everyone.
A．While
B．Because
C．Since
D．When
现场摄像机编码采用的是？一共有多少位？
