先天性主动脉缩窄的X线表现为()
A.肋骨切迹
B.3字征
C.升主动脉扩张
D.上纵隔阴影增宽
E.降主动脉上段的狭窄后扩张
参考答案:A, B, C, D, E
— We expected you yesterday.
— I'm sorry, I you to say that I couldn't be here until today.
A.must have called
B.would be calling
C.could have been calling
D.should have called
菌种退化