Acid and base react with acid or a base. If an acid is a strong acid aqueous solution shows properties. If there is any solution to best show the properties as a base.
Acids and bases react with acids or bases, then left. If the remaining acid solution showed the acidity. If the base is left, it will show the property was based solution.
Acid and base, already have reacted acid or base left. If the remaining acid solution showed resistance to acid If the base remaining solution would show treasure as bass.