The professor has written another book ____ of great importance to computer science.
A. which I think it is B. and I think is
C. which I think is D. when I think is
The professor has written another book ____ of great importance to computer science.
A. which I think it is B. and I think is
C. which I think is D. when I think is
C
I think是插入语。A答案中的it是多余的。