21. —Good morning , May I help you ?

—Oh, thank you. I’m just looking around.

—_______________.                                                    

A. Thanks for coming to see me .   B. How are you feeling today?

C. I’ll write you a check right now.  D. Take your time , then.

22. What shall we use for power when all the oil in the world has ______?            

A. given out   B. put out   C. held up      D. used up

23. Now, ______ were we? Oh yes, we were talking about John.     

A. how                         B. where                   C. what                     D. who