Answer:
The ones in Bold are the answer
1 : spider, most search engines use a computer program called a "spider" to collect information and index web resources. Sometimes called "web-crawlers" or "robots"
2. searches a database of information according to the user's query of
4. step 3 : frequent search
5. Crawler based search engines.
Human powered directories.
Hybrid search engines.
Other special search engines.
has to be one of those I guess
6. metasearch engine known as an aggregator, is a search engine that sends queries to several search engines and either aggregates the results into one master list or categorizes the results by the search engines they come from.
Explanation:
Hope it helped have a good night and good luck :-) !!!
