— Is Tom still smoking?
— No. By next Saturday he ＿＿ for a whole month without smoking a single cigarette.
A. will go
B. will have gone
C. will have been
D. has been going
网友回答
A. will go
(答案→)B. will have gone
C. will have been
D. has been going
解析：by 后跟将来的时间状语时，主句要用将来完成时。go without 意为“在缺……的情况下对付”。