I am sorry I can’t meet you at the station. I by the time you come back from abroad.A. a

问题补充：

I am sorry I can’t meet you at the station. I by the time you come back from abroad.

A. am leaving

B. had left

C. will have left

D. have left

答案：

A. am leaving

B. had left

(答案→)C. will have left

D. have left

解析：考查时态。by+过去的时间，主句使用过去完成时；by+将来的时间，主句用将来完成时。by the time you come back from abroad所知的时间是将来，故主句用将来完成时，即will have done sth。故选C。