The police ____(search) for the thief these days ,but they haven't found him yet
问题描述：
The police ____(search) for the thief these days ,but they haven't found him yet
答
have been searching
从下文 but they haven't found him yet（可他们还没找到可见,这个动作还在进行之中,故用现在完成进行时
请在客户端右上角评价点“满意”即可,为什么不是were searching呢？从状语these days （这些天） 和下文they haven't found 。。。。这个时态可见，陈述的是现在的事， 不能用过去进行时， 这样时态不一致