- Will you get there by _____ train?

- No, I'll take _      taxi.

A．/; a

B．a; the

C．/;/

D．the; a .

铝、铁、铜、银四种金属导电性依次增强的是（　　）

A．铝、铜、银、铁

B．银、铁、铜、铝

C．铝、铜、铁、银

D．铁、铝、铜、银