问题
选择题
I am sorry that I can not meet you at the airport. I Changsha by the time you come back from abroad.
A．am leaving
B．will leave
C．will have left
D．have left
答案
答案：C
考查时态。根据时间状语by the time you come back from abroad在他从国外回来之前，可知用将来完成时，故选C。