narrow something down缩减
narrow w down缩小范围;使变窄
narrow it down缩小;锁定重点
narrow w down the topic细化题目
narrow the topic down把题目范围缩小
narrow an argument down缩小议论范围;限制争论的范围
Narrow down topic缩小话题范围缩小
Narrow down the hall站务大厅
narrow down to变窄
PHRASAL VERB（动词词组） If you narrow down a range of things, you reduce the number of things included in it. 缩减
What's happened is that the new results narrow down the possibilities.
现有的情况是，新的结果缩小了可能性的范围。