题目内容：

the scholar has made another breakthrough in this field,___of great importance to the progress of science.
A.i think which is B.which i think it is C.about which i think it is D. which i think is
我想知道原因 谢谢您的帮助

优质解答

选D这道题主要考两个知识点：1 插入结构,2 定语从句其中 插入语i think 可以直接去掉,而不影响定语从句的完整.同时,which作为关系词,指代的是前面的先行词breakthough（突破）.整个定语从句可分解为the breakthough(...