根据分子量大小不同进行分离的方法是
A．结晶或重结晶B．溶剂沉淀法C．酸碱沉淀法D．盐析法E．透析法
参考答案：E
It was quite a serious mistake, ____caused by carelessness.
A．which I think was
B．I think which was
C．which I think it was
D．I think which it was
劳神过度易损伤的脏腑是 （）
A.心肝
B.肝肾
C.脾肾
D.心脾
E.脾肺
