正常肢体动脉的血流频谱形态是()
A.宽频三峰递减型血流频谱
B.低阻力型血流频谱
C.高阻力型血流频谱
D.三相血流频谱
E.收缩期双峰、舒张期三峰血流频谱
参考答案:D
I think physics is _____ interesting subject. [ ]
A. /
B. a
C. an
D. the
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