AND operator

[GAA]

See code below:

SELECT * FROM Results WHERE
((Name = '%%SelectName%%') AND (Activity = '%%SelectActivity%%')) OR
((Name = '%%SelectName%%') AND (Venue = '%%SelectVenue%%')) OR
((Name = '%%SelectName%%') AND (Purpose = '%%SelectPurpose%%')) OR
((Activity = '%%SelectActivity%%') AND (Venue = '%%SelectVenue%%')) OR
((Activity = '%%SelectActivity%%') AND (Purpose = '%%SelectPurpose%%')) OR
((Venue = '%%SelectVenue%%') AND (Purpose = '%%SelectPurpose%%')) OR
((Name = '%%SelectName%%') AND (Activity = '%%SelectActivity%%') AND (Venue
= '%%SelectVenue%%'))

Why does the very last AND get replaced with an OR operator when you run
this query?