Usually if you have a blood clot in the lung, it comes from somewhere else first (such as the leg) then travels up the vein into the lung. You could get blood clots from trauma, prolonged sitting or bed rest and surgery.
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.