Do you know Guangzhou tomorrow?A. whether they leave for B. whether will they leave forC.

问题补充：

Do you know Guangzhou tomorrow?

A. whether they leave for B. whether will they leave for

C. whether they are leaving for

答案：

解析：C 考查宾语从句。宾语从句用陈述句语序，B是疑问语序，排除B。A项时态不对，表将来用will+动词原形或be going to do sth.句型。故选C。