I heard the elliptical machines are the most efficient while being the easiest on your body. But since I hate that machine it is not the best. The best cardio in my opinion is the one you like the best and makes you use it more and longer.
Therefore I opt to run and bike because I enjoy that. Mountain biking keeps me interested and my adrenaline up so I actually want to ride instead of feeling like I need to ride. Hope that helps, just find something you enjoy!
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.