40.It is usually warm in Changchun in early spring, but it _________ be rather cold sometimes.

A. must　　　 　　　　 B. can　　　　 　 C. should　 　　　　　　 D. would

39. -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.