目前,诊断肺动脉瓣狭窄首选的无创影像技术是()。
A.X线平片
B.CT
C.PET
D.MRI
E.超声心动图
参考答案:E
I don’t think I am ____ ; it is said that _______- is the mother of success.
A.a failure; failure
B.failure; a failure
C.a failure; a failure
D.failure; failure
德国地理学家李约瑟最早提出“丝绸之路”的概念。