答案：C

题目分析：句意：你认为还有多长时间中国和日本能够结束冲突？do you think是插入语，它用疑问句的形式，它的后面应该用陈述语气，故排除AB；这里it wiil be +some time before +…表示还要过多久才能……。

点评：本题难度适中。插入语在近几年的高考中经常出现，有插入语的句子增加了试题的难度，考生如果分不清插入语与句子的其他成分，很容易判断错误；固定句式不仅在单选中考查，还会出现在完形和短文改错中。

即学即练：He made another wonderful discovery, ____ of great importance to science.

A. which I think is    B. which I think it is

C. which I think it   D. I think which is

解析：A。这是一个非限制性定语从句， which 在从句中作主语，代替 the discovery .做这类题目的方法是先将插入语 I think 去掉，然后再将句子还原成为 He made another wonderful discovery， which is of great importance to science. 问题就迎刃而解了。