What was one result of large armies traveling great distances during the crusades? 1)europes population severly declined 2)democracy in the middle east grew 3)cultural diffusion increased 4)slavery was eliminated

Ibelieve it would be d hoped this !

True blindness may be caused by trauma to the eye, severe conjunctivitis due to  ibr (infectious bovine rhinoceros) or pink eye or other infections, leptospirosis, lead poisoning, selenium toxicity, fungal infections, vitamin a  deficiencies, rabies, vitamin b12 deficiency, neoplastic of the orbit or  conjunctiva, cataracts, congenital malformations, etc. 

What effect did the development of trade have on settlement patterns in medieval times