问题补充:
By the time we reach that page, we twenty lessons of the book.
A. will study
B. will have studied
C. would study
D. have studied
答案:
A. will study
(答案→)B. will have studied
C. would study
D. have studied
解析:这题考查时态,时间是:By the time+时间状语从句,“到…时间为止”,主句用相应的过去时,因为时间状语从句用的是一般现在时代替将来时,所以主句用将来完成时。句意是:到我们学到那一页为止,我们将已经学了20课了。选B。