有关脊麻时低血压的原因,哪项正确()
A.阻滞交感神经节前纤维
B.阻滞支配肾上腺髓质的神经
C.阻滞副交感神经纤维
D.肌肉松弛
E.术前脱水
参考答案:A
He is much better and can now.
A.get ahead
B.get about
C.get along
D.get away
A.,正电荷
B.,正电荷
C.,负电荷
D.,负电荷