问题
选择题
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
答案：C
题目分析：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。