It really depends on the specific language and API you are using. In C for instance, event-handlers are usually implemented as functions. In C++ they can also be callable objects.
Other languages may offer different options.
It may depend on the language. Event handler is a function which often has a special parameter (in most cases) where the parameter is the event object.
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.