经济落后的发展中国家，要缩小与发达国家的差距，加强( )尤为重要。

A．经济发展

B．体制改革

C．宏观调控

D．基础建设

Speaker A: Uh, I wonder if I could possibly use your phone.
Speaker B: ().

A. Oh, I’m sorry, but it isn’t working; it’s out of order.

B. You are welcome. It’s over there.

C. Of course. Who are you going to call

D. Yes, you can, But don’t you see a public phone booth over there