用酸性染料比色法测定的生物碱类药物，有机溶剂萃取测定的有色物是

A．生物碱盐

B．指示剂

C．离子对

D．游离生物碱

E．离子对和指示剂的混合物

—James is good at sports. He plays _____basketball well, and he plays _____piano well, too.

—Wow, he’s so good.

A．the, the

B．/ , /

C．/, the

D．the, /