Is there an adapter for a Vivitar 28-200mm manual focus for a Canon 550d?

That switch is there to speed up autofocus. In simple terms it allows you to tell the lens "don't waste your time looking for focus under 3.5 meters cos my subject is way over there". If your subject is further than 3.5 meters use the 3.5-infinity setting to get faster focus.

If it is below 3.5meters away or fast focus is not an issue use the full range 1.5-infinity.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.