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All of these yield different results. They are searched for in different volumes and with varying intent on the part of the searchers. You would do well to put a great deal of time researching which keywords to target, from the obvious "trophy" terms to the looooong tail. Based on that, craft copy incorporating as many terms as you can while remaining readable and easy to follow. Understanding that Google (and basically all other search engines) treat these queries differently is essential for SEO.