问题补充：
---Look! Here comes the bus and I have to go now.
Thank you for coming to see me off.
--- Goodbye, .
A. congratulations
B. cheer up
C. all the best
D. go ahead
答案：
A. congratulations
B. cheer up
(答案→)C. all the best
D. go ahead
解析：可联系答.案.网客服索取。
