Protoptype curved trestles are made from "deck plate girder" units, and those are always straight, unless the trestle is made from timbers, in which case a curved trestle is possible. The famous Keddie Wye (true name: Spanish Creek Trestle) is made from all straight DPG sections. Only the decking is curved.
Peter If the deck girder was curved, the torque when a train went over would rip it from it's mountings.... more.
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.