您好,By the time you receive this letter, I _____ this city for my home town.
A．have left B．will have left
C．leave D．will leave
与by the time 连用的句子应该用什么时态,主要是看这个时间点发生在过去还是现在或将来.you receive this letter 是将来的时间点,所以题目中的这句话应该用将来完成时.答案是B.
By the time l got to the station,the train had already gone.