耳硬化骨导听力曲线呈V形下降常在哪个频率,可参照图回答()。
A.250Hz
B.500Hz
C.1000Hz
D.2000Hz
E.4000Hz
参考答案:D
帕金森病的主要生化病理特征是()
A.5-HT减少
B.ACh减少
C.NE减少
D.DA减少
E.GABA减少
_____ work did they have to do that they had no time to take a rest at that time.[ ]
A. Too much
B. So much
C. Too many
D. Such little