单选题 By the time you get back, I ______ all the work.
A. would finish B. will have finished
C. has finished D. had finished

【正确答案】 B
【答案解析】[考点] 动词的时态
[解析] by引导的时间短语通常和完成时态连用。“by the time you get back”表示将来的时间，因此主句应用将来完成时态，故选B。