— Putting on a happy face not only helps us make friends but also makes us feel better.  

— _______.    [ ]

A. I can't agree with you more.      

B. It's up to you.     

C. It's my pleasure.                

D. Don't mention it.

国家:政府:行政( )

A．公司:经理部:经理

B．野战军:作战部:参谋

C．董事会:经理部:职员

D．总司令:军官:命令