How to choose between DTD and XSD?

It's probably important to learn DTDs as a separate exercise, just for the knowledge of how they work in case you encounter them somewhere else, and so that you can appreciate some of the things that XSD was trying to solve.

It wouldn't hurt to understand the structure of a DTD (it'll help you better understand an XSD in the long run)...but you should use XSDs moving forward.

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.