由于长时间接触噪声导致的听阈升高、不能恢复到原有水平的称为()。
A.一般性听力阈移
B.听力阈移
C.深度性听力阈移
D.永久性听力阈移
参考答案:D
We________finish it ahead of time, though it was such a tough task.
A.could
B.would
C.were able to
D.ought to
用亲脂性溶剂提取具有碱性的游离生物碱,正确的方法是()
A.1%HCl水溶液渗滤提取
B.EtOH回流提取
C.C6H6回流提取
D.药材加Na2CO3液湿润后,用C6H6渗滤提取
E.药材1%HCl加液湿润后,用C6H6回流提取