The search has narrowed down to a few streets where the gunman might be hiding.
搜查的目标已经缩小到几条街道了,那持枪的歹徒可能就藏在那里的什么地方。
narrow sth ⇔ downThe police have now narrowed down their list of suspects.
警方现已缩小了嫌疑犯人数的范围。
In the end the choice was narrowed down to three people who might be suitable for the job.
最后,只剩下三人可供选择,看谁更适合干这种工作。