When we use "on delete cascade" constraint in mysql?

You turn your computer on and the computer will not boot up where is something you should do to diagnose the problem?

Which parts of a presentation should be the most general? a. introduction and conclusion b. introduction and outline c. outline and conclusion d. outline and body

Someone plzz me which of these defines a social search? a. asking a search engine a question that is answered by a real person on the other sideb. modifying search results based on popularity of a web pagec.modifying search results based on a ranking of a web page