单项选择题
A.1950 B.1960 C.1965 D.1970 E.1972
A.10% B.50% C.20% D.80% E.60%~70%
A.双输尿管狭窄 B.输尿管结石 C.下尿路梗阻 D.膀胱肿瘤 E.输尿管畸形