professional search engine

• 专业搜索引擎

professional search engine的用法和样例：

例句

1. Focused crawler can fetch large quantities of domain resources from the Web in a short time.It is very helpful in both foused search engines and data mining companies.
   定题爬虫能迅速获取网络上特定主题的大量信息，对专业搜索引擎及数据挖掘应用都具有重大价值。