How can a speaker use quotations effectively in a speech?

What will be an ideal response?

Quotations are effective when another writer or speaker has expressed an opinion on your topic that is more authoritative, comprehensive, or memorable than what you can say. When the person you are quoting is not widely recognized, you should include a brief statement of his or her qualifications.Although a quote can effectively introduce a speech, you should not fall into the lazy habit of turning to a collection of quotations every time you need an introduction. There are so many other interesting, and sometimes better, ways to introduce a speech that quotes should be used only if they are extremely interesting, compelling, or very much to the point.