He has made a discovery ( ) of great importance to the progress of science and technology.

2023-05-26

A. which I think it is
B. which I think is
C. I think which is
D. of which I think it is


参考答案:B

考查定语从句。该句中discovery是先行词,放到句子中是I think the discovery is of great importance。不需要it,故选项B正确。A项多了个it,排除;C项语序错误,排除;D项不符合英语表达,排除;答案选B。