碱中毒时手足搐搦的原因是()。
A.神经肌肉兴奋性增高
B.伴低钾时可有硬瘫
C.蛋白结合钙增加
D.乙酰胆碱释放增多
E.游离钙减少
参考答案:A, C, D, E
11.My father stayed in Japan only a few months, _____he went through a series of hardship.
A.during which time
B.in time of which
C.where
D.Whenever
钢材存在明显的韧性-脆性转变温度,当温度降低至某个临界值或区间会出现()的突然下降。