从植物药材浓缩水提取液中除去多糖、蛋白质等水溶性杂质的方法为( )
A.水提醇沉法B.醇提水沉法C.醇提醚沉法D.铅盐沉淀法E.酸提碱沉法
参考答案:A
I hold it in my hands as if holding all the lives in the world, ______what to do with it. [ ]
A. didn't know
B. not knowing
C. not having known
D. not know
简述艺术在人类文化中的地位。