四肢血管正常的多普勒频谱波形是()。
A.单相波
B.双相波和单相波
C.双相波
D.三相波
E.单相波和三相波
参考答案:D
解析:四肢血管正常的多普勒频谱波形是三相波。
—What is he like?
—_____________.
A. He likes basketball.
B. He is very shy.
C. He is a boy.
D. He comes from the USA.
湘江一桥以南正在建设的一条过江隧道叫什么?