-What does your father do?
-He is __________ art teacher.[ ]
A. a
B. an
C. the
D. /
答案:B
肺动脉瓣血流的多普勒频谱的特点是()
A.收缩期为正向,舒张期为负向,尖峰形状
B.收缩期出现,负向,单峰
C.持续全收缩期,负向,正弦波形状
D.舒张期出现,双峰形状,正向
E.收缩期正向,双峰,舒张期负向,波峰圆钝
当事人对当场处罚决定不服的,有权提起行政诉讼。()