Answer:
Letters and publications written by Nazi leaders before the Second World War.
Explanation:
This answer is correct because this historian is searching for the motives of these perpetrators, letters and publications can tell their thoughts and conversations.
The aquaducts supplied Rome with freshwater.
It took place in 1812 to 1814
Goethe said that the doctrine of Copernicus was the only one that had a great effect on the human spirit above all.
For the first time in the human history men renounced the privilege of being the center of the Universe, it gave a freedom of vision and greatness of thought.
Goethe was a great influence for the modern culture, art and science. He concieved the individual as a small world, existing by his own means as a result of the Copernicus Heliocentrism theory.
Maybe include the factors you can choose from.
