Amajor cause of pollution in medieval cities was

Unclean way of life

Explanation:

People in the Middle Ages didn't care much about hygiene. The streets were filthy, you could see different animals wandering on the streets, and the rats were spreading diseases across the cities.

This is why in the Middle Ages more people died out of sickness than out of some other cause.

in 1897, pershing became a tactical officer at west point, and that's where he was given the nickname "black jack." pershing's first name is "john," for which "jack" is a nickname, and he was a white man who commanded black troops. hence "black jack".

(1)representation based on state population (2)all states have equal representation apex