He made another wonderful discovery ,___of great importance to science .

问题描述:

He made another wonderful discovery ,___of great importance to science .
A.which I think it is.B.which I think is

选B,which引导的是定语从句,I think是插入语可忽略不看,直接判断which it is和which is,从句主语是the discover可以省略,所以选B