大黄泻下通便，正确的用法是
A．伤阳助寒 B．伤阴助火 C．收敛邪气 D．伤津败胃 E．助湿满中
参考答案：C
As he ________ in the river for five hours, the thief looked very pale and hopeless. [ ]
A. trapped
B. has been trapped
C. trapping
D. had been trapped
红霉素以游离分子形式存在时，可用吸附法分离，吸附时发酵液的pH应调节（）。
A.大于7
B.小于7
C.等于7
D.2～12
