问题补充:
The professor you referred to in the letter us students three lectures by next Monday.
A. has given
B. will given
C. will have given
D. Gave
答案:
A. has given
B. will given
(答案→)C. will have given
D. Gave
解析:考查时态。you referred to in the letter是定语从句,省略了who/that,by next Monday到下周,by+将来的时间,与将来完成时连用。句意:你在信里提到的那位教授到下周,将已经给我们学生做过三次讲座了。故选C。