—I am going to spend my summer holiday in Hainan.
—How lucky you are! And don’t forget to e-mail me.
A. Congratulations!
B. Have a nice time!
C. Come on!
D. Good-bye!
网友回答
A. Congratulations!
(答案→)B. Have a nice time!
C. Come on!
D. Good-bye!
解析：在情景对话中，怎么客气，怎么婉转？