患儿，16个月。形体极度消瘦，面色无华，神疲乏力，腹凹如舟，足踝及颜面浮肿，小便不利，舌质淡嫩，苔薄白，指纹淡。其血生化检查中最重要的异常改变是（）

A.球蛋白明显低于正常

B.白球蛋白比例倒置

C.血清总蛋白降低

D.白蛋白低于20g/L

E.白蛋白低于25g/L

In fact _____ is a hard job for the police to keep order in an important football match. [ ]

A. this

B. that

C. there

D. it