________ parents may have a stronger desire to see their children step into the world of ________.[ ]

A．Poor; rich  

B．The poor; rich

C．Poor; the rich  

D．The poor; the rich

最常用的检测细胞因子的免疫学检测方法是

A．免疫层析
B．发光免疫
C．ELISA
D．细胞增殖法
E．斑点杂交