Question

he has made a discovery,_______ of great importance to the progress of science and technology.

he has made a discovery,_______ of great importance to the progress of science and technology.
A.which I think is B.that I think is C. I think which is D.of which I think it is
答案选A 请解释一下为什么 并且 分析一下其他选项！！

Answer 1

A，因为这个是非限制性定语从句，那么引导词肯定要放在前面了，所以肯定是which在前，排除C，而且非限制性定语从句，引导词不能用that，排除B，然后就看A和D，这个定语从句的先行词是discovery，放到从句里就是I think the discovery is of great importance，根本不需要有it，所以选A，这个句子的意思是他的发明对科学技术的进步很重要。