— What do you mean        saying “The boy is overgrowing”?

— I mean that he is tall        his age.

A．about; with

B．as to; for

C．by; for

D．by; to

下列哪种酶不能用于标记抗体？（）

A.胰蛋白酶

B.辣根过氧化物酶

C.酸性磷酸酶

D.碱性磷酸酶

E.葡萄糖氧化酶