问题
选择题
The expert offered us another piece of advice,_____of great help to our program.
A.I think it is
B.I think which is
C.which I think it is
D.which I think is
答案
D
I think 为插入语,干扰了定语从句结构的判断,从句中缺少主语,不能省略。故选D。