“She's not a dancing teacher, is she?”“_____.”

A．Yes, and she isn't

B．Yes, but she was

C．No, but she isn't

D．No, but she was

下列哪项不是引起输尿管梗阻的常见原因()

A．输尿管结石

B．输尿管肿瘤

C．输尿管炎性狭窄

D．下腔静脉后输尿管

E．输尿管结核