In a moment of weakness I downloaded
Duck Duck Go.
At first DDG remained as an alternative, and at not time have I agreed to it being my default search-engine, yet it has infiltrated Firefox and established itself as such.
(Oh, how I hate software that does that!)
\\how do I restore my previous favourite (Google)?
Do I have to uninstall DDG - or is there a a menu setting that will rectify the situation?