问题
选择题
The visiting professor gave us some advice,________ of great help to our English learning.
A．I think it is
B．I think which is
C．which I think is
D．which I think it is
答案
答案：C
题目分析：句意：来访的教授给我们一些建议秒我认为这对我们的英语学习很有帮助。Which引导的是非限制性定语从句，在定语从句中which做主语，I think是插入语，所以选C。