单选题 He has made another discovery, ______ of great importance to science.
A. which I think it is B. of which I think it is
C. which I think is D. I think which is

【正确答案】 C
【答案解析】句意为“他又有了另一个发现，我认为这对于科学界具有非常重大的意义”。本题考查： (1)非限制性定语从句，详见34题所述；(2)插入语。严格意义上说，插入语并不算句子成分，只是起到补充说明的作用。