颈椎不稳的主要诊断依据之一，是过伸过屈位椎体角度位移大于（）。
A.15°
B.12°
C.11°
D.10°
E.9°
参考答案：C
Tom's uncle knows computers well, and he a computer engineer. [ ]
A. maybe
B. may be
C. may be is
D. may is
瞬态响应包括哪两个方面的问题？
