—Look！Here comes the bus and I have to go now. Thank you for coming to see me off. —Goodby

问题补充：

—Look！Here comes the bus and I have to go now. Thank you for coming to see me off.

—Goodbye，and！

A. congratulations

B. all the best

C. cheer up

D. go ahead

答案：

A. congratulations

(答案→)B. all the best

C. cheer up

D. go ahead

解析：考查交际用语。A祝贺你；B万事顺利，一切如意；C振作起来；D去做吧！句意：—看，公交车来了，我得走了。多谢你来为我送行。—再见，一切如意。故B正确。