问题
选择题
Doctor Smith has made another wonderful discovery, _______ great importance.
A．which I think is of
B．which I think it is of
C．which is I think
D．I think which is
答案
答案：A
题目分析：句意：斯密斯博士做出另外一个发现，这我认为是很重要的。这里使用了非限制性定语从句，修饰discovery，which在定语从句中做主语，I think是插入语，选A。