--- Tommy is planning to buy a car.
--- I know. By next month, he enough for a used one.
A. saves
B. saved
C. will save
D. will have saved
网友回答
A. saves
B. saved
C. will save
(答案→)D. will have saved
解析：本题考查时态。By +时间状语，往往用完成时态，再根据next month可知用将来完成时，选D。